1. Sustainable Remediation
and the Landscape Architect
A Dissertation Submitted in Partial Fulfilment of the Requirements
for the Degree of
Master of Arts
in
Landscape Architecture
by
Jenny Charlotte Hill
BIRMINGHAM
City University

2. ii
I‘d like to take this opportunity to thank my advisors and supervisors Kathryn Moore and
Richard Coles for listening to me and helping me construct this work. I am also grateful
to all the other people at BIAD and in the wider world who answered my many
questions. My family and Duncan have my gratitude for sponsoring my dreams, and for
locking me in the study.

3. iii
“Design is not just what it looks like and feels like.
Design is how it works.”
Steve Jobs

4. iv
Abstract
This paper considers how risk management within public landscapes can be worked into
design strategies, and so attempts to make sustainable remediation technologies a more
appealing option in contaminated land reuse and development.
To achieve this, a review is undertaken of current legislation and drivers relating to the
reuse of land and in particular contaminated land. Opening the landscape armoury,
firstly a summary of weapons against site contamination is considered. This is followed
by an attempt to determine the shields that are available to be designed into potentially
hazardous landscapes.
A number of professional projects are studied for indications that design against risk can
be worked into comfortable yet contaminated environments, particularly those
undergoing long term sustainable remediation. Finally, a critical review is undertaken of
a piece of the authors own design work on a contaminated site, to look at remediation
measures undertaken and interventions against risk to humans and the environment.

5. v
Contents
Contaminated Land ...................................................................................... 1
Greening and Reuse...................................................................................... 4
Sustainable Remediation ................................................................................ 5
Risks........................................................................................................ 8
Economic ..................................................................................................... 8
Property Price on Site ...................................................................................... 9
Speed ........................................................................................................10
Relative Cost................................................................................................10
Fit-for Purpose..............................................................................................11
Social.........................................................................................................11
Perceived Risk ..............................................................................................12
Property Values and Loss of Amenity ....................................................................12
Environmental ..............................................................................................13
Human Health...............................................................................................13
Toxicology ...................................................................................................15
Sustainable Remediation Solutions ...................................................................17
Monitored Natural Attenuation (MNA)...................................................................17
Biotechnologies.............................................................................................18
Phytotechnologies..........................................................................................19
Phytostabilization ..........................................................................................20
Phytoextraction.............................................................................................20
Rhizofiltration ..............................................................................................21
Phytodegredation and Phytovolatilization..............................................................22
Hydraulic Control...........................................................................................22
Rhizodegradation...........................................................................................23
The role of Spontaneous Succession.....................................................................25
Remediation and the Landscape Architect ..........................................................27
Risk and the Landscape Architect.....................................................................28
Masterplanning Strategies..............................................................................29
Zoning........................................................................................................30
Thoroughfares ..............................................................................................31
Detailed Design ..........................................................................................31
Vertical Barriers ............................................................................................31
Fencing ......................................................................................................32

6. vi
Planted screens.............................................................................................33
Water as barrier to pathway..............................................................................33
Water as source.............................................................................................34
Signage.......................................................................................................34
Change in Height ...........................................................................................34
Horizontal Barriers .........................................................................................36
Decking and Bridges........................................................................................36
Surface Treatments ........................................................................................36
Deterrent Paving ...........................................................................................37
Restfulness ..................................................................................................37
The AMD & ART Project,...................................................................................40
Pennsylvania, USA..........................................................................................40
Landschaftspark, Duisburg Nord, Germany.............................................................43
Markham Willows,..........................................................................................47
Derbyshire, UK..............................................................................................47
Victor Civita Plaza,.........................................................................................51
São Paulo, Brazil............................................................................................51
Gasworks Park, .............................................................................................54
Seattle, USA.................................................................................................54
The Ford Rouge River Complex, Dearborn, USA .......................................................57
West End Heating Plant, DC, USA .....................................................................61
Sensitive Receptors ........................................................................................64
Space.........................................................................................................64
Planting......................................................................................................66
Lupinus.......................................................................................................67
Panicum virgatum ..........................................................................................68
Saccharum giganteum .....................................................................................69
Populus nigra ‗Thevestina‘................................................................................70
Rock Creek ...............................................................................................71
Design........................................................................................................72
Species.......................................................................................................73
Maintenance ................................................................................................74
Control.......................................................................................................74
Conclusions...............................................................................................75

7. vii
Figures
Figure 1 Adapted from Pollard (2001), a similar diagram is found in (SEPA, 2009) who describe
the category on the left as ―Land subject to change of use dealt with through development
management‖................................................................................................... 1
Figure 2 Multi-media-model, adapted from (Cowan, 1995).............................................. 2
Figure 3 Adapted from (Surf-UK, 2010) ..................................................................... 5
Figure 4 All the time in the world? Adapted from (Bridges, 2010) ...................................... 6
Figure 5 a) ―Montitored Natural Attenuation‖, b) ―Bioremediation‖, and c) "Phytoremediation"
timelines, from keyword 'hits' in scholarly articles (google, 2010). Note that whilst effort has
been made to scale the x axes, the y axes are entirely independent of one another................ 7
Figure 6 Oily (Briar, 2009)..................................................................................... 8
Figure 7 Land reuse for housing (DEFRA, 2010)...........................................................10
Figure 8 Risk matrix for human harm. Adapted from SNIFFER (2009) .................................11
Figure 9 Source -> Pathway -> Receptor (images from Kounadeas, n.d and NASA, n.d.) ...........14
Figure 10 Keep Out!...........................................................................................14
Figure 11 Natural Attenuation (Sinke, 2010) ..............................................................17
Figure 12 Accessing an injection port (Scharfe, 2009)...................................................18
Figure 13 cross section through biowall showing visual impact on surface, adapted from (Parsons,
2008) ............................................................................................................19
Figure 14 Phytoextraction....................................................................................20
Figure 15 Sunflowers (hoosier_buddy, n.d.)...............................................................21
Figure 16 Tanner Springs Park (naturalsystemsinternational, 2009) ...................................23
Figure 17 Sidwell school wetlands courtyard (Pruned, 2009) ...........................................24
Figure 18 Subsurface Horizontal Flow Rhizofiltration. Adapted from (Initram, 2010) ..............25
Figure 19 Buddleia colonising an abandoned site.........................................................25
Figure 20 Remediation of an Oil Refinery (Fan, 2007) ...................................................28
Figure 21 City of Baltimore zoning (Roland Park, 2007) .................................................30
Figure 22 Zoning for use (Port Deposit, n.d.) .............................................................30
Figure 23 Desire line turned social trail across a corner between a primary and secondary road
(Pugh, 2007) ...................................................................................................31
Figure 24 Fences, more than functional (Demarkesvan, 2010).........................................32
Figure 25 Down edge, Up Edge (Walker, 2005) (Exceledge, 2010) .....................................35
Figure 26 Park for a Rainforest (Johanson, 1992) ........................................................36
Figure 28 Decorative?.........................................................................................38
Figure 28 Aggressive? .........................................................................................38
Figure 29 Yellow boy (DIRT, 2007)...........................................................................40
Figure 30 Masterplan (AMD+ART, 2007) ....................................................................41
Figure 31 view down the treatment ponds (Levy, 2010).................................................41

8. viii
Figure 32 Sign in situ: warning and to educating about the function of the landscape.............42
Figure 33 Sign to explain the artistic concept behind the landscape..................................42
Figure 34 The Wilderness (Spekking, 2006)................................................................44
Figure 35 (ayurvediccure, 2008) ............................................................................44
Figure 36 Walkway over the Sinter Garden (Latz, 2010) ................................................45
Figure 37 Bunker garden, much of it only visibly accessible from above (Latz, 2010). Signs direct
the viewer to the ‗Wumfarne‘ or worm ferns growing on the walls in the chambers below. ......46
Figure 38 The separation of the Emscher (culverted under the path) from the rainwater canal.
(Landschaftspark, 2010)......................................................................................46
Figure 39. Markham Vale Masterplan (Vector Design Concepts, 2010).................................47
Figure 40 Parent skeleton of 'dioxins'.......................................................................48
Figure 41 Detail of North tip (AEA Technology, 2004b)...................................................48
Figure 42 Conceptual Model for Risk assessment (AEA Technology, 2004) ............................49
Figure 43 Markham Vale Environmental Centre...........................................................50
Figure 44 Ground Plans Praca Victor Civitas (Dietszch, 2008) ..........................................51
Figure 45 Section of platform (Dietszch, 2008)...........................................................52
Figure 46 Relationship of platforms to existing vegetation (Dietszch, 2008).........................52
Figure 47 Tec Garden: as planned for the Praca Victor Civita, and as presented as a commercial
product with Remaster Technology (Dietszch, 2008, Abbud, 2010) ....................................53
Figure 48 Wetland and raised 'Tec garden' platforms. In the background the platform bends up
and over to form a roofed structure in the centre of the space. (Espinillar, 2010) .................53
Figure 49 The site of Gas Works Park in 1965 (REF)......................................................54
Figure 50 NW quadrant masterplan (Berger, 2003).......................................................55
Figure 51 Street view of the Northern side of the NW Quadrant. Note the concrete wall, left
unscrubbed and just around eye height. (Google, 2010) ................................................56
Figure 52 Green roof at Rouge complex (The Henry Ford, 2010) ......................................57
Figure 53 View of the water treatment ponds, on the left and the wildlife orchard, centre
(teycosa, 2007)) ...............................................................................................58
Figure 54 Rouge plant concept (Bargmann, 1999)........................................................59
Figure 55 Rouge plant Masterplan (Bargmann, 1999) ....................................................59
Figure 56 Sunflowers at Ford plant (The Henry Ford, 2010) ............................................60
Figure 57 Information sign on Rouge complex (The Henry Ford, 2010) ...............................60
Figure 58 Site Perimeter (Hill, 2010).......................................................................61
Figure 59 Storage Yard from nearby Expressway .........................................................61
Figure 60 Rusted and leaking tanks prior to removal from the site (Veterans Development Corp.,
2010) ............................................................................................................62
Figure 61 Site boundary wall from the East ...............................................................65
Figure 62 Minimalist fence by Mas and Fernandez (2007) ...............................................65

9. ix
Figure 63 Lupinus polyphyllus 'Camelot Red' (Schram, 2009) ...........................................67
Figure 64 Lupinus polyphyllus 'Gallery Blue' (Jyoti, 2008)...............................................67
Figure 65 Lupinus arboreus: Native and Invasive .........................................................68
Figure 66 Panicum virgatum 'Heavy Metal' (Jason, 2009)................................................69
Figure 67 Switchgrass roots (Renich, 2008)................................................................69
Figure 68 Poplar nigra 'Thevestina' (Vmenkov, 2007).....................................................70
Figure 69 CSO point in Rock Creek Park (Vosa, 2009) ....................................................71
Figure 70 Rock Creek Treatment Wetland .................................................................72
Figure 71 Iris versicolor (Boréal, 2007) ....................................................................73
Figure 72 Lobelia Cardinalis (Schaumburg Community Garden Club, 2010) ..........................73
Figure 73 Classical representation of gravity well as a surface (rendered in Sketchup, Google)..75
Figure 74 Egg Tempera (Kluz, 2008) ........................................................................76

10. Page | 1
Contaminated Land
Within the UK the definition of contaminated land has been altered over the years
subject to political concern and developers lobbying. Today, in England, Wales and
Scotland we have a definition provided within the Environment Act 1995, Part IIa:
―Contaminated land‖ is any land which appears to the local authority in whose
area it is situated to be in such a condition, by reason of substances in, on or
under the land, that—
(a) Significant harm is being caused or there is a significant possibility of such harm
being caused; or
(b) Pollution of controlled waters is being, or is likely to be, caused;
Furthermore
―Harm‖ means harm to the health of living organisms or other interference with
the ecological systems of which they form part and, in the case of man, includes
harm to his property.
This legal instrument also provides the authority for the regulation with which to
establish the significance of any harm caused. The latest of such regulations in the UK is
a ‗Circular‘ published by DEFRA (2006) which helpfully contains appendices defining
terms such as ‗likely and ‗significant‘ as well as outlining the method of risk assessment.
(See Risk).
Figure 1 Adapted from Pollard (2001), a similar diagram is found in (SEPA, 2009) who describe the
category on the left as “Land subject to change of use dealt with through development management”.
Derelict
Land
Land defined as
‗Contaminated‘
Land with some
contaminants present

11. Page | 2
From the illustration on the previous page we can see that not all contaminated land is
derelict, but the scope of this thesis covers any land subject to redesign or
redevelopment. It can also be seen that of all the land which may be affected by
contamination, only a small proportion is subject to legislation governing its remediation
for use. It has been previously estimated that between 1 and 4 % of land bearing some
contamination has then been deemed to require priority treatment to mitigate a hazard
(Perry, 200). (See Extent)
The land obviously doesn‘t exist in isolation from the other matrices of the environment
and contaminants do flow from one phase to another according to miscibility, viscosity
and volatility. This is a simple manifestation of the 2nd
Law of Thermodynamics which
can be summarized:
―Nature Abhors a Gradient‖ (Schneider, 2006)
Figure 2 Multi-media-model, adapted from (Cowan, 1995)
The guidance document from DEFRA (2006) also includes an appendix on the pollution of
controlled waters; notable in this is section A.37
―Land should not be described as contaminated land where:
a) A substance is already present in controlled waters,
b) Entry into controlled waters of that substance from the land has ceased; and
c) It is not likely that further entry will take place.‖
Sediments
Soils
Water Bodies
Air
Groundwater
Precipitation

12. Page | 3
This makes it quite clear why the extent of contaminated environments is difficult to
assess. To be sure, if a lake or other water body contains dissolved pollutants, or oily
pollution on the surface, as long as it is not being added to at the time of observation, it
is not ‗contaminated land‘.
Another reason why defining contamination is so terrifically difficult lies in our
increasing sensitivity to ‗contaminants‘. Our technological capability to detect more and
more minute trace of chemicals grows almost weekly. Many common compounds are now
readily detectable down to parts per billion (ppb) and these are tiny amounts.
To put this into context, hydrogen cyanide gas is generally understood by most people to
be toxic or at least not good for you. The Health and Safety Executive inform us that
working for 8 hours in an environment containing up to 10 parts per million Hydrogen
Cyanide gas, borders acceptable (HSE, 2007).
But desktop technology means that we can detect up to 100,000 times less than this
(TDL, 2006), so clearly just being able to sense a chemical doesn‘t automatically render
it harmful. For this reason many countries adopt a risk assessment basis for determining
the severity of contamination present on a site. (See Risk Assessment, and Fear for
further discussion).
The difficulty in defining contaminated land lies at the heart
of the problem in measuring it. In the UK many recent sources
still cite a report by the Environment Agency (2002), which
stated that as many as 20,000 sites within England may be
‗contaminated‘; affecting up to 300,000 Ha, which reportedly
approximates 150% the area encompassed by the M25
(Hutchins, 2002), or 1/40 the area of England.
By 2007 a follow up report was produced (EA, 2007), which
found that in the intervening five years just 781 sites had been
positively identified and 90% had been administered by the
planning system, rather than requiring higher intervention (invocation of Part IIa). It was
also remarked upon that over 90% of the ‗contaminated‘ sites had housing upon them at
the time of inspection. This illustrates the tighter thresholds for action on this type of
land as well as the tighter scrutiny under which it is used and maintained by the owners.
The distinction of contaminated sites is complicated in the USA owing to a variety of
relevant state and federal laws, but a recent summary estimated that across America
there may be over 100,000 individual sites requiring attention at any given time (EPA,

13. Page | 4
2010). Environment Canada report having tens of thousands of contaminated sites
(Environment Canada, 2009), and in China it is estimated that up to 10% of the total land
may be significantly effected (Qi, 2007).
Greening and Reuse
Urban post-industrial brownfield sites are usually in prime locations, owing to the
transportation requirements of the previous occupants. Railways, major roads, canals
and or coast are often alongside or nearby having been used to bring in fuel and raw
materials and to export finished goods.Many such large facilities were built in the
decades around the industrial revolution; the urban fabric has since been woven around
them, so that as the cities have grown these sites become effectively closer to the city
centre and the potential land value increased in response.
Various policies have been aimed directly at this reserve of unused space including,
during the last UK administration, incentives to build high density dwellings. However, a
growing school of thought demands that these opportunities to embed green spaces into
our cities, and thus enrich the lives of surrounding communities, are not overlooked or
wasted (Cl:AIRE, 2009).
Whilst many of larger brownfield sites are strategically well placed to provide economic
benefits both locally and sub-regionally, and have the potential to provide urban
extensions or in-fill, their development is resisted by the perception that they are
―problematic‖ (English Partnership, 2006). This is reference to the potential clean-up
required by the developer if contamination is discovered on site and if those causing the
pollution cannot be found or held to account (surprisingly common for historical
industrial sources).
English Partnership also recognises the value of ―Greening‖ inner city sites, to reduce
anti-social behaviour and to improve the wellbeing of the local community. In the very
next sentence of their report, they go on to say that
―Remediation of contaminated sites is a major bonus of brownfield development.‖
(English Partnerships, 2006)
The compatibility of these two agendas is echoed by the Forestry Commission (Perry,
2000), who opine that as behaviours differ in landscape types, urban woodland is a much
less ‗risky‘ use than domestic gardens for example.

14. Page | 5
Sustainable Remediation
Sustainability with regard to our actions in the (re)development of land is defined by the
balancing of social, economic and environmental costs/benefits. This balancing act is
the source of risk associated with each of the factors. These risks have impact on all the
stakeholders; the local community, the investors, the wildlife etc. SURF-UK defined the
principle of 'Sustainable Remediation' (based on the Brundtland Commission, 1987
document):
―The practice of demonstrating, in terms of environmental, economic and social
indicators, that the benefit of undertaking the remediation is greater than its
impact...‖ (CLU-IN, 2010)
Figure 3 Adapted from (Surf-UK, 2010)
All remediation techniques may be categorised and ranked thus:
Destruction>Recycling>Removal>Stabilisation>Containment
Obviously techniques which effectively destroy the contamination are at the more
desirable end of the spectrum, with containment being the last resort (Nathanail, 2004).
These traditional priorities are being shaken by the energy expenditure and
unsustainable nature of 'removal' as an option. Removal has previously meant to an
appropriately lined landfill elsewhere, or more recently can mean to a facility where a
range of techniques can be applied to the matrix ex-situ. However, increasing
Economical
Social Environmental
Bearable
ViableEquitable
Sustainable

15. Page | 6
environmental awareness and economic cost of translocation will drive forward
alternative, in-situ treatments. Another factor when considering in-situ or ex-situ
approaches is the disruption caused by excavation as demonstrated in the graph below.
Figure 4 All the time in the world? Adapted from (Bridges, 2010)
Drawn together under the heading ‗Low Energy Remediation‘ the treatments considered
here are:
 Monitored Natural Attenuation
 Bioremediation
 Phytoremediation
The uptake of these techniques was the subject of an online seminar earlier this year
(CLU-IN, 2010). Agencies from around the world came together to present each national
or region picture in terms of drivers for and constraints against the use of ‗Sustainable‘
or ‗Green‘ remediation techniques.
Overall it appeared that the organisations from the USA were by far the most advanced
in terms of actual deployment and field scale studies, and that they had the resources
and the power to disseminate their findings most widely. European and Canadian
counterparts reported fewer drivers toward the use of Sustainable techniques, by way of
regulation or market forces, and more constraints in the way of risk adversity,
scepticism and conflicting interests amongst project teams.

16. Page | 7
It may be that these measures need a sort of dynamic marketing campaign to inspire
authorities and developers alike. Whilst the technology is being employed in small scale
ways all over the place, Iconic landscapes employing these techniques are few and far
between. The delegates of the seminar were in agreement that the list of case studies
was short and well-trodden.
A survey recently conducted by the Network for Industrially Contaminated Land in
Europe concluded that sustainable remediation measures were still viewed as being a
relatively new concept (NICOLE, 2009). This is supported by recent correspondence I
have received from the UK Environment Agency:
"(phytoremediation) is quite a novel and specialist way of dealing with soil
contamination.‖ (Holehouse, 2010)
Looking at the number of published articles regarding these techniques it appears that
the wider deployment of these techniques will be due in the next few years.
Figure 5 a) “Montitored Natural Attenuation”, b) “Bioremediation”, and c) "Phytoremediation"
timelines, from keyword 'hits' in scholarly articles (google, 2010). Note that whilst effort has been
made to scale the x axes, the y axes are entirely independent of one another.
a)
b)
c)

17. Page | 8
Risks
A hazard is any situation which has the
potential to cause harm; a relevant
example would be a small body of
standing water with an oily film upon
it. Typically, most hazards are dormant,
so the contaminated water, for
example, is causing no trouble to
whatsoever when subject to no
external forces.
A risk is the evaluated potential of the
hazard to cause a particular harm (HSE,
2006). For example, these
hydrocarbons could pose a toxic threat
to living organisms that drank the water, or even pose a fire threat under some other
extreme circumstances.
Risk assessment is the stepwise process undertaken to consider all the potential
outcomes relating to a particular hazard, and evaluating their impact on future
activities.
Risk management is the prescription of mitigation measures required to reduce the risk
to an acceptable level. Note that the nature of the world is such that no risks can be
entirely excluded under any measures. Such responses therefore need to be
proportionate, and returning to our example, such management may be the provision of
personal protective equipment to someone whose job requires that they handle the
water.
The definitions outlined above apply not only to risks to health or safety, but translate
also into the language of business, where the risks faced by stakeholders may include
financial loss or negative publicity.
Economic
Firstly, under the heading ―Appetite for Risk Returns‖, the following was reported this
month.
―Investment in clean technologies doubled in the second quarter of 2010 compared
to the first 3 months of the year‖ (RSC, 2010)
Figure 6 Oily (Briar, 2009)

18. Page | 9
A review of the economic factors affecting uptake of phytoremediation has been
undertaken by a US/UK team (Linacre, 2005). They used an algebraic model to assess
the impacts of: Property price, phytoremediation cost, alternative treatment cost and
the speed of phytoremediation. The potential influence of the Landscape Architect is
considered for each of these factors below.
Property Price on Site
Industrially contaminated sites within urban confines are typically much smaller than
those in rural locations owing to property prices at the time of construction and location
of raw materials. Therefore, in most cases these smaller sites will be the more costly
per unit area and as such investors will require a greater return upon reuse. This drives
for techniques that give a quick, reliable clean up so that land can be built upon (the
assumption here being that the financial yield buildings per unit area outweighs that for
parkland).
So it appears that this factor relates directly to the politics of a country with regard to
brownfield reuse in urban areas. Where green space retro-fitting into cities is being
encouraged or facilitated by the government, the potential exists for high profile phyto-
technological landscapes on old industrial sites.
In the UK the Landscape Institute (2009) have published a position statement on Green
Infrastructure and CABE provide best practice guidance on open space strategies for
urban locations (2009)
Land use policy has though been, to target brownfield land for housing and commercial
development. Although the coalition has abolished minimum housing density targets
(Barclay, 2010), it is not yet known how this may affect the implementation of larger
scale urban greening projects.

19. Page | 10
Figure 7 Land reuse for housing (DEFRA, 2010)
Having a different system of representation in the US, ASLA calls for visitors to their
Advocacy website to write a letter to or even to Tweet their representative regarding
their Campaign for Urban Parks (ASLA, 2010).
Speed
The authors of the economic review suggest that remediation taking more than three
years would be intolerable for stakeholders and regulators, unless ―special conditions for
the site are granted.‖ In many cases this may not be achievable through
phytotechnologies. These special conditions could incorporate restricted access to
certain areas of a site or limited land use on a wider scale, so called institutional
controls (US Environmental Protection Agency, 2010).
Relative Cost
For the purposes of their calculations the ‗Alternative technologies‘ were estimated to
cost approximately twenty times that of phytoremediation per unit area. This serves to
illustrate the degree of adversity to project failure, and the hindrance this poses to
‗emerging‘ techniques like Phytoremediation. Driven by market forces, commercial
clones developed for specific clean up tasks would become cheaper and more widely
available with increased specification by engineers and designers. The paper instead
addresses a potential doubling of costs relative to the alternatives and finds that in all
cases the phytoremediation option becomes unviable.

20. Page | 11
Fit-for Purpose
Finally, from the economic paper, based upon the current estimate of the cost ratio of
the technologies, a land value of 1000 USD/ha and a clean-up period of ten years, the
team conclude that in order to be a viable proposition Phytoremediation has to have a
probability of success greater than 0.7. Another way of looking at this is to say that the
investors have to consider the chance of failure (not fit-for-purpose after project) as less
than 30%.
By addressing both the ‗purpose‘ and the ‗fitness‘ it should be possible to increase the
‗odds‘ of success. Here masterplanning and detailed design could be employed to
mitigate risk to individuals using the site and so rebalance the fitness for purpose.
Social
Figure 8 Risk matrix for human harm. Adapted from SNIFFER (2009)
Problems can occur where there a mismatch between the real and perceived risks of
harm from contaminated environments. Where there is too little concern for the hazard
(too much ‗comfort‘), careless behaviour can endanger human health and or the
environment. Where the fear of the threat posed is over inflated, the dangers faced are
economic as well as human health through undue stress.
It is the job of the remediation team to inform the local community as best as they are
able to help equip them with the knowledge they require to make informed choices
about their use of the landscape. Whilst a landscape may be challenging, awe inspiring,
Low Risk
but
High
perceived
Risk
High risk
&
High
perceived
risk
Low risk
&
Low
perceived
risk
High Risk
But
Low
perceived
risk

21. Page | 12
formal, exposed… … most users would want it to provide some comfort due to natural
survival instinct. As contaminated land can make individuals very fearful, this
rebalancing of perception can be important in ultimately creating a useable space.
Perceived Risk
Communicating with stakeholders regarding the land contamination and the proposed
remediation measures is both complex and usually emotionally charged because of the
potentially serious implications of the problem, the diverse range of people involved and
the competing priorities.
Visual tools such as diagrams or pictures are essential to adequately include all groups
during consultation. These may include sketches of views of the development proposed,
photographs of the type of technologies to be employed, or conceptual site models,
similar to flow charts to illustrate potential routes of exposure and mitigating measures.
This presents the designer, as a visual communicator, the opportunity to come together
with technical professionals to assist in the dissemination of such material.
Effective communication does not entail conveying what is perceived by the experts as
the ‗real risk‘, but must be based on an understanding of the differing perceptions of
risk based on situations and values of those affected.
Public stakeholders often have concerns over a range of risks – real or feared only, on a
range of topics (SNIFFER, 2010). Presented in no particular order, these may include:
 Personal Property Values
 Loss of Amenity
 Damage to the Environment
 Human Health
Property Values and Loss of Amenity
The design of the repurposed landscape presents an opportunity to maintain or even to
enhance domestic and commercial land values in an area. In fact, in some cases the risk
lies in the potential ‗gentrification‘ of an area through the remediation, where strong,
exciting designs are employed in development attracting rapid investment into a
neighbourhood.
Property values may well decline though in the short term whilst environmental
contamination has been exposed and made public, but before a remediation strategy has
been convincingly implemented.
People tolerate a variety of risks I their everyday lives; but most people want to be able

22. Page | 13
to have some level of control over these risks. Land contamination is perceived to be
riskier that activities which pose a clear risk to health and safety (e.g. smoking
cigarettes or driving). This is because:
 Exposure to land contamination is usually involuntary,
 There is generally less familiarity with it and the associated risks; and
 There is more uncertainty over what is ‗safe‘. For these reasons, people may
want to be able to exercise as much control as possible over the proposed reme-
diation measures.
In situations where otherwise derelict land is transferred to a green urban space this is
likely to improve amenity for the community surrounding, but this can come at a cost
where the site is already under unofficial use (Turner, 2008)
Stakeholder involvement in the design process, can form an important part of
empowering communities and individuals in this regard as well as presenting an
opportunity to educate the population about the remediation technologies involved.
Environmental
To comply with all regulation, minimisation of the risk to the wider environment is
largely concerned with ensuring that the contamination is not spread off of the site.
Sensitive receptors specifically referred to include surface water, groundwater passing
out of the site and, within the UK framework, Sites of Special Scientific Interest (DEFRA,
2006). Airborne contamination is not specifically ruled against, instead being covered by
threats to human health. Larger plants such as trees used in dendroremediation may
well contribute to a reduction of air borne pollutants also (Nowak, n.d.)
Obviously any treatment regime that is undertaken in-situ will minimise the risks posed
to the wider environment by not transporting the waste about the place. With water
posing here as potential source, receptor and pathway, the challenge lies in ensuring
that the treatment regime is sufficient to treat the effluent rapidly enough so that the
existing rate of spread is halted.
As raised later, an important factor when treating contamination using complex
biological processes is to ensure that overall bioavailability is reduced rather than
increased during the treatment period.
Human Health
These fears are often about the individuals own health, but it is likely that most people
would also consider children and other particularly ‗sensitive receptors‘. Worries may be

23. Page | 14
experienced about future exposure as well as unwitting exposure already incurred. A
common concern is that of chronic exposure causing some sort of health ‗time-bomb‘ of
which the individual is unaware. Particular public fears are well known to exist in the
public consciousness about genetic mutations and cancer (Gardner, 2009).
Potential future exposure is that which the design team has the most control over,
although other experts such as analytical scientists or toxicologists may need to be
consulted in order to present information regarding all of these concerns.
Figure 9 Source -> Pathway -> Receptor (images from Kounadeas, n.d and NASA, n.d.)
Risk Assessment is Europe and N. America is conducted according to a
Source → Pathway → Receptor model (DEFRA, 2006).
Strategies to manage the risk focus on controlling the exposure of the receptor to the
contamination. This may be achieved one of three ways:
 Removal of the Contaminant – This is the traditional approach, where expedient
and ‗total‘ treatment is undertaken before any site reuse.
 By ‗breaking‘ or removing the pathway – This entails both design and long term
management of the landscape scheme to make the site useable whilst
remediation is undertaken. A simple method of pathway disruption would be to
lay an area to hard landscape for car parking rather than allotments growing
edible products; effectively minimising
the risk of soil ingestion.
 Protection or removal of the receptor –
It is envisaged that the ‗protection‘ of
receptors would be to provide suitable
personal protective equipment and
tools for maintenance crew and clean-
up engineers. Removing the receptors
Figure 10 Keep Out!

24. Page | 15
from the landscape serves to promote dereliction and would contribute to the
degradation of local community through negative perception of the local
environment. Unfortunately this has also been a traditional approach in some
areas.
Toxicology
There are four main routes by which chemicals may enter the human body:
• Inhalation - Absorption into the lungs is obviously only
going to be a problem for gases and vapours. The main
contaminants of concern in this route are Volatile (and Semi)
Organic Compounds (VOC's and SVOC's).
• Dermal Contact – Absorption in through the skin is more
likely to pose a threat in terms of chronic rather
than acute exposure. As such preventing ready or
convenient to the contaminated substrate may
provide adequate control of the risks posed. The
main contaminants of concern for this route are
some pesticides or herbicides.
• Ingestion – Absorption through the digestive tract may occur by
eating the soil or drinking the water. Where the concentration is very
high, smoking may also pose a risk of this pathway through the hand to
mouth action. All known contaminants should be considered a posing
some degree of threat through this route especially to children who may
exhibit pica behaviour around the soil or vegetation.
• Other Internal – Direct introduction beneath the skin may occur where cuts or
abrasions occur in the contaminated environment. Where a risk assessment deems that
there is a greater likelihood of such injury occurring, signs would be valuable in advising
first aiders or paramedics of the chemical present to
inform any decontamination measures required. Such
environments may include external dining areas
where glass may be routinely present, skate parks
where active behaviour is undertaken on a hard
surface, or at angling pegs.
By considering all of these potential exposure routes, it can be seen that some require

25. Page | 16
pathway removal i.e. to prevent inhalation of volatile compounds will require that
humans are kept well away from the water of soil from where they are being emitted.
However, the risk of some others like ingestion or internal exposures can be reduced to
insignificant levels by pathway ‗disruption‘ (pica noted). In the UK risk assessment of a
site remediation is usually undertaken as a three step process, largely for economic
reasons. The preliminary assessment establishes a conceptual model identifying the key
items listed above. Following this a generic risk assessment is undertaken using tools
which calculate risk based upon proposed site usage and contamination levels measured
in selected areas. Only after this stage has passed, is the model refined to encompass
site specific spatial arrangements and potential pathways.
This presents a hurdle for the landscape design team in that specific risk reduction
measures in the project would not be assessed until this stage where significant
investment will usually already have been made.

26. Page | 17
Sustainable Remediation Solutions
Monitored Natural Attenuation (MNA)
Gaia philosophy may state that the earth, as an organism, will seek to redress dis-ease
and so ‗heal; itself. Controversial though that theory may be, in the case of pollution in
the environment, this is roughly the case.
Whilst the technical mechanisms by which this degradation occurs are fascinating, they
are beyond the scope of this work, and the reader is directed to (Sinke, 2010) for an
easy to digest introduction to the subject. An excerpt features below.
Figure 11 Natural Attenuation (Sinke, 2010)
To understand and minimise the risks posed to the environment and the users of a site

27. Page | 18
these processes must undergo regular monitoring usually through sampling and mapping
of the contamination periodically. It is this on-going observation which distinguishes MNA
from doing nothing.
Biotechnologies
As stated above, bacterial activity occurs to reduce contamination without any help; as
such the term bioremediation is more usually used to imply that specific intervention
has taken place.
Microbiological action takes place aerobically, in the presence of air, to break down
organic materials such as hydrocarbons, or for chlorinated hydrocarbons (such as laundry
fluid) anaerobic bacteria (those that work without oxygen) are the more efficacious. In
either case the technique involves introducing a mixture of gases and or sustenance into
the matrix to promote the growth of the desired bacteria.
An example project has been undertaken at the Romic Environmental Technologies plant
in California, where cheese whey and molasses have been injected into the soil to
promote the destruction of chlorinated solvents using bioremediation (EPA, 2010).
For the treatment of ground water, barriers of suitable medium (often wood chip mulch
with added ‗soft‘ plant material) (Parsons, 2008) can be placed into the flow path to
provide remediation as the water passes through. In construction terms these ‗biowalls‘
are either continuous across the plume of
groundwater contamination or are used in a Funnel
and GateTM
arrangement using impermeable barriers
to direct the flow through a narrower space
(Naithanail, 2004).
In Bioaugmentation, the natural colonies of bacteria
are added to using one of the many commercially
grown strains tailored to the application
(Novozymes). The application of such material can
be made directly into surface water or is made
using one of the physical formats described above.
Figure 12 Accessing an injection
port (Scharfe, 2009)

28. Page | 19
Injection sites are non-obtrusive and where
multiple applications need to be made, the
surface is best laid to ‗soft‘ landscaping or hard
surfaces with easily lifted portions, or hatches
so that injection ports can be accessed i.e.
There is little or no overall implication for
landscape design.
As biowalls are typically topped with backfill
from the trench, after installation no special
considerations are given to the surface
treatment. The extent of the research though
indicates that most surface treatments to date
have been re-seeded with grasses or paved
rather than deeply rooted planting (Parsons,
2008).
Phytotechnologies
Phytoremediation (from the Greek 'phyton', meaning plant) describes all forms of
remediation employing plants as the means to reduce or remove contamination from an
environment. Using plants in this way offers the significant benefit of improving the
public perception of the site during clean-up by invoking a sense of cleanliness and
progress (US EPA, 2008).
There are several remarkable mechanisms of action and these dictate the suitability of
application in a given case.
They may broadly be categorised into:
Metals Organics
Phytostablization Phytodegredation
Phytoextraction Rhizodegredation
Rhizofiltration Phytovolatilization
Whilst considering definitions, ‗remediation‘ in UK legislation covers not only the clean-
up of the contamination, but also its detection. Interestingly BP have developed a series
of designed urban schemes in the US, termed ‗Phytoscapes‘, using selected species pre-
emptively around areas at risk of small scale oil spillage (Tsao, n.d.). These incorporate
‗canary‘ species intolerant of hydrocarbon contamination as well as those known to
Backfill from
trench
Groundwater
Movement
Impermeable
strata
Geotextile
membrane
Figure 13 cross section through biowall
showing visual impact on surface, adapted
from (Parsons, 2008)

29. Page | 20
actively reduce it if it should occur: The dying out of some of the planting scheme acting
as a catalyst for monitoring or further action as necessary.
Phytostabilization
This is the process where the contaminants
become sequestered in the soil within the
vicinity of the root systems rather than within
the plant tissues themselves. This reduces the
overall bioavailability and threat of exposure
to humans and all other above ground species.
This is coupled with the advantage of the root
system forming a physical network reducing
the physical movement of soil. In so doing this prevents more contaminated soil
underneath from being exposed. In the case of acid mine drainage (AMD), this can
prevent further oxidation of the iron pyrites, which is important in slowing or halting
further AMD production. Trees and deep rooted plants are preferred for this although
bryophytes have also been observed to play a role (Holyoak, 2008) (Adams, 2005). When
using a harvestable crop for stabilization, consideration must be given to whether
sequestration of the metals is desirable. This has been considered in relation to using
short rotation coppice to produce biomass for heat and power (Paulson, 2003).
Phytoextraction is undertaken by
particular natural or genetically modified
species that hyper-accumulate or store
dramatically higher concentrations of a
given metal or profile of metals within
their tissues than many other plants. This
technique is not without its benefits,
Sunflower crops (annual) have been
reported being able to extract and
accumulate lead up to 2% total dry mass, making the resultant harvest worthy of sale for
recovery of the metal. Indeed this property is being exploited by prospectors under the
name 'phytomining'. In other instances where the crop is not saleable for its unusual
content, the disposal of such vegetable waste can be problematic (Paulson, 2003).
Figure 14 Phytoextraction

30. Page | 21
Helianthus annus, a species
often employed in the
removal of heavy metals from
soil has many positive
associations from vacation or
even childhood memories, and
looking at field of them lifts
the spirits compared to an
open grassland or a derelict
site.
In reality though, permitting
them to flower can create
what is termed an attractive
nuisance. With metals stored in
the biomass, including the seeds, they are effectively making the contaminants more
rather than less accessible to non-human animals on the site, and thus recycles the
contamination in the ecosystem.
So, to remove the contamination from the system the treatment regime must include a
biomass removal stage. Where this is an annual species as above, this entails dedicated
plots of land being occupied by a succession of ‗crops‘ usually over a number of years.
These plots can be designed into a scheme where a point source is small enough to
warrant such a meadow on a site, but even then there will be several months of the year
in which the ground stands bare.
Metals may be present in soil from point sources where a building or facility has been
demolished. A non-point source of unusual metal contamination in the environment is
in acid mine drainage (AMD) which affects surface water. These two scenarios also differ
in that the source of the contamination has been removed in the first, so that over time
the net contamination is reduced. In the latter the contamination level requiring
treatment does not diminish over time as it is effectively replenished by chemical
processes unrelated to the remediation. This type of water based treatment typically
uses aquatic species and is usually distinguished under the term rhizofiltration.
Rhizofiltration
Used to treat metal contamination in surface water this technique employs similar
mechanism to the phytoextraction. Again studies into the translocation of the metal
Figure 15 Sunflowers (hoosier_buddy, n.d.)

31. Page | 22
materials within the plants must be considered to factor in the dangers posed to humans
and other animal users of the site, by the vegetable matter (Adams, 2005). However, the
rates of translocation are usually much lower in the aquatic species so that the metals
accumulate in the roots of the plants, requiring less harvesting maintenance and posing
a lower threat.
Due to the benefits gained by reduction in airborne particles, and the efficiency of this
technique, it is sometimes applied following dramatic flooding of contaminated ground
not previously below water (Otte, 2006). Conducting remediation of this sort obviously
has enormous implications for the landscape over a wide area, as these can be very
large sites in mountainous regions.
Phytodegredation and Phytovolatilization
As with phytoextraction, the undesired
contaminants are taken up from the soil by the
roots of the plant, but here they get broken
down by the metabolic processes of the plants.
The technique is largely applicable to organic
(hydrocarbon and related) compounds, and does
mean that the overall levels of the chemicals are
reduced within the system.
In phytovolatilization the breakdown products or
even the parent compounds are subsequently
transferred to the atmosphere via the leaves of the plants.
Risks may remain during the treatment process if the breakdown products themselves
are toxic to sensitive receptors such as wildlife or humans. E.g. Trichloroethylene (TCE)
may be broken down to vinyl chloride which is itself more toxic.
Hydraulic Control
Whilst not specifically a form of phytoremediation, using plants with very high
transpiration rates can effectively intercept and soak up contaminated groundwater on
its way to a sensitive receptor such as a nearby water course. Suitable species are
usually trees, due to their deep roots and high transpiration rate and include some
species of Populus and Salix (EPA, 2001) with recorded transpiration rates of 100-300 and
over 22,000 L/day respectively!

32. Page | 23
Rhizodegradation
This technique stimulates a variety of biological remediation mechanisms in the
rhizosphere (around the roots) below water level. When this technique is employed in
urban schemes it is often targeted at cleaning up storm water runoff, rather than
tackling existing groundwater or soil contamination.
Figure 16 Tanner Springs Park (naturalsystemsinternational, 2009)
In Tanner Springs Park, Portland, street runoff treatment has been incorporated into a
water system to evoke the marshy ground and creeks that previously ran through the
area. The natural water courses, the springs and streams remain culverted though as the
ground level has risen by approximately 6 m since these were last open (City of
Portland, 2010). Despite media attention given to acid rain, storm water runoff from
streets or roof tops is not usually regarded by the public as hazardous. Schemes designed
to handle this type of water do not require such stringent risk control measures, and are
increasingly being used in school grounds for educational purposes as well for
environmental benefit.
This water reprocessing scheme at Sidwell Friends School in DC, designed by Andropogon
Associates, does however have an inlet for black water (post settling) in the foreground
of the lower photograph. Under interview, Rachel Gutter, senior manager of the school
sector for the U.S. Green Building Council (USGBC) said that the plans for the wetlands

33. Page | 24
went through a "rigorous process with the D.C. City Council" to gain approval (US Green
Building Council, 2009). Reportedly the scheme was almost called off at the last minute
owing to concerns from the local health department, but was permitted on a pilot basis,
subject to a regular
monitoring regime
(Malin, 2007).
Today the school
website informs us
that the school uses
93% less water
through recycling,
that the water
undergoes further
filtration and UV
treatment after re-
entering the
building, achieves
the same standard
of cleanliness as
municipal water
supplies, but
despite all that is
still only permitted
for use in flushing
toilets (Sidwell
Friends School,
2010).
The buildings
surrounding the
scheme are the middle school with occupants mainly between 10 and 14 years of age.
Access to the treatment wetland is not restricted to students apart from the safety
barriers nearby the buildings where the water is deeper and more foot traffic is likely to
pass alongside. To reduce the health risk posed by the effluent, the scheme employs a
sub-surface flow system so that the water remains below the level of the substrate until
Figure 17 Sidwell school wetlands courtyard (Pruned, 2009)

34. Page | 25
it is cleansed, further downstream. This is one of the most useful techniques for all
publically accessible schemes for that reason.
Figure 18 Subsurface Horizontal Flow Rhizofiltration. Adapted from (Initram, 2010)
Because the water flow is restricted to the space within the matrix this format can be
prone to clogging compared to an open flow system (where the water appears on the
surface). However the benefits also include requiring less space than the open water
type, as well as achieving reduction in biochemical oxygen demand (a measure of
bacterial count) and suspended particles
(Tilley, 2008).
The role of Spontaneous Succession
Restoration Ecology paper presents
technical reclamation, i.e. planting to a
design as a direct alternative to
spontaneous succession. (Prach, 2008)
Whilst the authors do acknowledge that a
variety of site conditions can factor into
design decisions, intermediate options for
intervention, including sustainable
techniques, do not feature highly.
In rural locations, where predicted
pathways are few, the spontaneous style
may be appropriate; however in urban
surroundings this appearance would give a Figure 19 Buddleia colonising an abandoned
site

35. Page | 26
sense of dereliction without some clear framework or structure to the site. Also, in
urban settings with greater access and hence more pathway opportunities, the potential
risk from doing nothing is much greater.
Natural revegetation of a site can provide a useful palette of species tolerant of the soil
and water conditions which can inspire and enrich designs incorporating chemically
functional species also, or provide suitable structure and décor to a scheme undergoing
monitored natural attenuation (Adams, 2005).
Using information regarding spontaneous revegetation, the Forestry Commission has
been able to challenge previously held beliefs about the feasibility of establishing
woodland on contaminated sites owing to the retardation expected in tree growth
(Hutchings, 2002).

36. Page | 27
Remediation and the Landscape Architect
Prospective Landscape Architects in the UK are informed that:
―This work often involves environmental remediation and reclamation, which is the
process of cleaning and restoring land and water that have been damaged or polluted.‖
(LI, 2010a) Yet the Landscape Institute bears no reference to contaminated
environments in its Position and Policy documentation (LI, 2010b) leaving little in the
way of formal guidance about the role of the Landscape Architect in these matters.
The American Society of Landscape Architects does have a position paper published on
Water, saying:
―ASLA encourages land use practices that… …eliminate all forms of water pollution‖
These two organisations are compared as they both have the power to confer the
professional title Landscape Architect, and through this research it has become apparent
that the scope of their work differs.
Candidates put forward for professional examination in N. America (LARE) are expected
to have a working knowledge of subjects such as ―land and water reclamation
procedures‖ and ―biofiltration and other alternative drainage methods‖. (CLARB, 2007)
The Syllabus for the Pathway to Chartership scheme administrated by the Landscape
Institute (LI, 2009b) does not cover any specific design knowledge, instead focussing on
professional practice and legal matters.
Of the various low energy/sustainable remediation techniques being developed,
phytoremediation is the most obviously related to landscape architecture through the
use of plants. Worldwide courses are educating in the techniques of phytoremediation
and their role in designed landscapes, as demonstrated by some of the recent output
from California State Polytechnic (Brown, 2005), Suny College of Environmental Science
and Forestry (Mendel, 2002), University of Virginia (Ring, 2006) and The University of
Melbourne (Fan,2007).

37. Page | 28
Amongst many
others not cited
here, the
perception in each
of these pieces of
work is that of
working with
something entirely
novel and unheard
of before. Whilst in
reality plants have
been employed as
machines for
decades already.
The Landscape
Architects of the future will probably take all these considerations in their stride as we
continue to use and reuse land. For now though, we stand on the brink of a revolution,
waiting for and prompting the mainstream to get on board with these integrated
solutions. The prospect of employing a long term remediation strategy through the use
of plants requires that species selection is also tailored to the contamination as well as
other environmental conditions. In addition to this, where pressures on land require that
it be reused for development, some control must be exercised to protect the site
occupants and visitors whilst the clean-up is underway.
Risk and the Landscape Architect
In the UK the Commission for Architecture and the Built Environment (CABE) have taken
part in a growing debate about the rights and responsibilities the public have in using
their own shared space (CABE, 2007). The argument is one of promoting more
stimulating environments in public spaces versus the fear of damage to people, property
and ‗Quality of Life‘ not to mention litigation which can trouble councils and private
land owners. The cover of this publication features an individual leap-frogging a bollard,
and this focus on the potential for physical harm is carried on throughout. CABE have
since confirmed that chemical risk is not within their remit and enquiries resulted in a
reference to CIRIA (Halliman, 2010).
Figure 20 Remediation of an Oil Refinery (Fan, 2007)

38. Page | 29
Masterplanning Strategies
Lynchian elements and ideas for spatial arrangements of cities have application on all
scales down to individual sites. The flow of people through and around paths, edges,
districts, and landmarks is also analogous to the movement of pollution through the soil
on the groundwater stream. With pooling, points sources and non-point sources of
contaminants, barriers to and speed of flow all providing rich data for the remediation
team.
To reduce pathway linkage between receptor and source, the following strategies are
recommended:
• To place main thoroughfares and nodes away from highly contaminated areas.
• To reduce loitering in contaminated areas where paths do cross through
• To provide physical barriers between source of contamination and receptors
(reduce proximity)
• To 'zone' areas of higher contamination to avoid inappropriate uses or regular use
by most sensitive receptors. Note though that land uses which usually do not include
children such as industrial or business parks are not accounted for separately in risk
assessment tools currently (Environment Agency, 2010).
Assuming that the human receptors are now on the site, and in closer proximity to areas
posing a hazard, the challenge lies in either breaking or sufficiently disrupting the risk
pathway so that they may go about enjoying the landscape in relative safety. In a review
undertaken of the risks posed by a new water feature in Brindley Place, Birmingham, the
Design Response included the stipulation that:
―People should use common sense when using the space‖ (CABE, 2007)
Whilst it may seem that doesn‘t need saying, all too often a fear of risk has meant that
project teams have not been able to take it for granted. When considering the design
elements below, this principle has been broadly applied, although it is understood that
people will make the landscape their own, through their actions.
Inspiration for elements of ‗control‘ is drawn from diverse fields of landscape including
inclusivity of access, physical risk management, security and agriculture.

39. Page | 30
Zoning
The simple spatial mapping to
determine types of land use
prior to development has been
undertaken in many jurisdictions
for decades. On a wide scale as
illustrated in the city of
Baltimore, this can cause
frustration for developers by
controlling the nature of their
investments. Criticism is also
levelled at the potential
monotony of the landscapes
created within and that the
population migrate en mass from
one area to another at set times
of day contributing to
congestion on the roads or
public transport, and leaving
behind deserted
neighbourhoods; residential during the day, commercial at night.
On a more local scale zoning a
site to accommodate
contaminated site is essential.
From where to run overground
watercourses and where to grow
vegetables, through to
consideration of schools as
recetacles for more sensitive
receptors.
Figure 22 Zoning for use (Port Deposit, n.d.)
Figure 21 City of Baltimore zoning (Roland Park, 2007)

40. Page | 31
Thoroughfares
From the idea of ‗zoning‘ more sensitive uses away from more contaminated areas it is
sensible to assume that major pedestrian and cycle routes must also be diverted safely
away from areas under treatment. However, this is a ‗risky‘ strategy, as by missing the
desire lines of the local population, there is a greater likelihood of regular desire lines
resulting in so called social trails or cow paths.
Resultant damage to the vegetation, which
may have been effectively capping
contaminated earth may become worn to such
a degree that dust is raised, and the soil itself
becomes accessible to young children. For this
reason, the priority must be to provide some
sort of capping or land covering along desire
lines and this can unfortunately turn out to be
an iterative process for minor routes.
A lot of minor detours can be reduced though
by reducing the number of acute angles formed by paths along beds or lawn, or be
providing suitable discouragement from taking 'cross country' routes (see detailed design
strategies).
Even more importantly, looking at the wider picture, where the Landscape Architect has
the opportunity to develop a functional and beautiful site, diverting the visitors away
from the ‗exhibition‘ negates the requirement to design for human aesthetic concern.
Detailed Design
These rely in part to the slight physical inconvenience of gaining access. When selecting
an impediment to movement on this basis, consideration must be made to the 'dare'
factor. The 'dare' factor is defined as the desire by users to use the landscape in a
slightly 'alternative' manner. Whilst most people are not accomplished freerunners,
children in particular may walk along the top of a low wall or anyone in a playful mood
may leap a narrow water course for the entertainment value.
Vertical Barriers
Here this is used to describe all forms of barrier or deterrent that works alongside
individuals rather than below them. A huge palette of landscape options are available to
control behaviour in this way, from tall and slim fences, to low and wide canals.
Figure 23 Desire line turned social trail
across a corner between a primary and
secondary road (Pugh, 2007)

41. Page | 32
Fencing
One of the most common barriers,
fences take up the least horizontal
space, and provide an economical
option. Employed either to prevent
or just to discourage passage, the
purpose of this mitigating measure is
to break the pathway. In its
specification, consideration must be
given to the design objectives
whether that is to enclose or to
maintain visual connectivity through
to the other side. Social paths are
most likely to form when a visual link can be made to the destination, and the structural
integrity must be able to prevent or withstand occasional breaches. Guidance on the
protection of controlled areas warns that whilst fencing provides a strong psychological
deterrent, it only provides limited entry delay to ―motivated aggressors‖. (ASLA, 2009).
Walls
Above waist high, the wall provides a strong barrier to access. Seat walls of
approximately 0.6 m can perform as a
multi-functional edge to soft
landscaping.
Below this height, if a desire line
crosses the wall, its function even as a
psychological barrier is severely
impeded to the physical able.
Figure 24 Fences, more than functional (Demarkesvan,
2010)

42. Page | 33
Planted screens
From hedges to wide decorative beds, this covers a
wide variety of physical options providing that
approximately speaking the height plus the width reach
a minimum level. Representing the tall and narrow,
hedges, usually reserved for visual screening, can
prevent ingress providing that they have a strong core.
This can be provided by the inclusion of a fence barrier
within or alongside, or traditional hedge-laying
techniques employed for centuries for stock control.
Where herbaceous or lower shrubby planting forms part of the remediation measures,
increasing the decorative aspects (colour of blooms or foliage, or form and overall bed
structure) can deter ingress through behaviour modification (see change in height).
Water as barrier to pathway
Whilst areas of surface or ground water may be unsuitable for public contact, separate
self-contained circulations may be employed in channels, fountains or falls. Areas of
standing water are possible within schemes but they may require periodic monitoring to
ensure that they do not end up sinks of contamination in the long term.
Normal stride length for an adult male is approximately 1.4 m (Perry, 1992); this means
that in order to provide a visual clue or a psychological barrier to access, around 0.7m
width is required, because above that an individual would have to be sufficiently
motivated to make a small leap. For a grown adult or teenager, the width between 1 m
and 1.4 m may present sufficient challenge to provide this motivation (the 'dare' factor).
For this reason channels between 0.7 and 1.0 m would be expected to provide the
strongest barrier. However, young adults and children come in many sizes and where a
smaller width is selected as a visual barrier there will always be some to whom the jump
will provide some entertainment.
Two factors can raise the water channel to a much more robust barrier. Where space
permits bodies of water greater than 1.5 m this would also provide excellent hindrance.
Alternatively where the channel width is restricted, the far side of the channel can be
designed so as not to provide any clear landing space, putting off those that would
traverse deliberately.
The depth of the water will contribute significantly to the effect of the barrier. Shallow
well lit water with a clear and clean lining may well attract paddlers and waders in

43. Page | 34
warmer weather. For this reason, darker linings to such channels and maintaining a
depth at least 0.5 m would put off most casual visitors as this deters wading with rolled
trousers. This depth would allow easy access into the water for maintenance or should
the need arise in an emergency. (CABE, 2007).
Water as source
In many parts of the world, the public has direct access to the edges of contaminated
surface water bodies. The hazards associated with this are:
 Deliberate entry onto the water either in person or in a small boat.
 Other entry into the water through accident or malice.
Deliberate entry into the water can be largely mitigated though signage. Such
installations could simply advise that there is to be 'No Swimming' or may inform the
reader further about the risks associated with that particular water course in order to
further dissuade entry. Accidental entry into the water can be prevented by providing
well marked and stable edges to the water body. Mid height barriers may be required in
some circumstances and as mentioned previously sub surface flow beds can treat water
whilst minimising risk to all terrestrial receptors.
Signage
Signs work be appealing to the intelligence, and as such will work best when clearly
legible and attractive to draw the attention.
These same signs are important in emergencies, as they help first responders navigate
through the site to their destinations as quickly as possible.
While signage should identify areas where people can go, they should not (unless
required by regulation) identify sensitive areas that are restricted. To do so may attract
unnecessary attention.
Change in Height
Based on the physical attributes alone, the height of a retained feature will be directly
related to the frequency with which it is overcome. Changes in height which occur with
the path on the lower side will attract casual seating up to a certain height, as
mentioned above. To present a reasonable degree of physical challenge, this height is
determined by how high an adult can get their hips from a standing vertical jump;
approximately 1.3 m (based on an average British male aged between 18-29, 174 cm
tall, and weighing 75 kg) (Goldsmith, 1979)(Body Mass Index Chart, 2010)(ExRx, 2010).
However, vertical obstacles much lower that this can be effective in some situations.

44. Page | 35
It has long been recognised that our surroundings
govern our behaviour, and empirical studies
published in Science magazine confirmed this (Keizer,
2008). The team found that when unwitting subjects
were asked not to chain a bicycle to railing or had a
flyer left on their bicycle or found an unattended €5
note, the number of deviant responses rose
dramatically when the surroundings had graffiti or
litter present.
As the problem posed here is one of preventing
entry, deviant behaviour is considered any effort to
overcome the barrier to gain access. The desire to
enter is not automatically associated with deviancy
in the mind of the subject, as retrieving a lost article
or wanting to photograph a landed insect may also
drive someone to enter an area.
The degree to which a landscape element presents a
psychological barrier is indirectly related to the
degree to which it must pose a physical challenge.
That is to say that in very formal surroundings as little as a few centimeters of
difference in the height of the land may deter many from accessing the lawn or planted
area.
However, the researchers also found that when a single bicycle was already chained to
the fence, the rate at which others did so rose dramatically. This can be likened to a
single group of young people choosing to sunbathe on the formal grass ‗giving
permission‘ to all other passers-by to do the same until the
lawns are full on a sunny day. The ‗trick‘ to this sort of
control, is to prevent any single visible act of deviancy
from taking place to prevent all others from doing the
same. Of course, the findings also demonstrate the
importance of maintaining a clean and tidy ‗cared for‘
appearance in areas where deliberate control of access is
attempted.
Figure 25 Down edge, Up Edge
(Walker, 2005) (Exceledge, 2010)

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Horizontal Barriers
Decking and Bridges
Figure 26 Park for a Rainforest (Johanson, 1992)
Whilst this model demonstrates an effective way to reduce risk to individuals from
contact with the soil, this piece of land art is designed to bring the visitors into close
proximity with the trees. Tree top walks are appealing and easily made accessible to all,
when employed over a plot undergoing dendroremeditation (that specifically employing
trees) an assessment would need to made of the translocation of toxic compounds to
leaves and other growing portions of the trees used. Decking need not be high off the
ground to form an effective barrier and a floating deck may be an attractive and
functional design intervention connecting over-land to over-water.
Surface Treatments
The manner in which the surface is presented will dictate the potential for exposure of
users. An environment that invites the passer-by to stop and sit will need to be
countered by stronger measures to prevent contact between the user and the
contaminant of concern. Sometimes, the surface treatment can also function as a
chemical remediation, such as the application of limestone chippings being used to raise
the pH of underlying acidic coal waste (Nathanail, 2004).

46. Page | 37
Deterrent Paving
A number of manufacturers
produce 3D paving modules which
are specifically designed to
reduce the attraction of
particular paths. These are often
employed at the edge of roads to
discourage pedestrians from
crossing in a dangerous location,
or alongside buildings to improve
privacy for residents. Generally
they are not considered to be
highly attractive but do provide
inspiration for other textural
surface treatments that discourage access. As a landscape element they are usually
regarded plain or unattractive and their use is restricted to small areas and utilitarian
settings.
Redesigned to improve the aesthetics, a textured surface would in likelihood become
more of an attraction than discouragement and in some locations may encourage play on
the area.
Restfulness
To disrupt risk pathways in public environments it may be desirable to both increase
mean pedestrian speed as well decrease visitor density. To achieve both of these aims,
One may set about designing areas of moderate control, which are accessible but
uncomfortable, without inducing fear. According to proxemics theory, pedestrian speed
should increase along narrower pathways as we attempted to increase our personal
space in public. Conversely, wide open spaces invite individuals to pause and enjoy their
own space within the landscape.
To reduce human exposure, climatic functions could be manipulated by the Landscape
Architect to reduce the time spent in an area. People are unlikely to stop and rest or
consume food in an area too hot or cold, too windy or exposed, or too noisy. Discomfort
induced through these measures is unreliable though and unlikely to pass muster with
regulators.

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The blog ‗Design with Intent‘ by Dan
Lockton (2010) has highlighted the
social intentions of various seating
designs found internationally. The
findings have application here, where
a variety of seating may be positioned
throughout a public square of plaza,
with the more 'restful' or user friendly
seating in the areas where it is
preferred that visitors may stop to
consider their environment for longer
periods and in perhaps eat their lunch.
Other seating described as 'Anti-user'
could be employed in areas of high
pedestrian speed, to provide short rest
stops only to those passing through.
Preventing extended periods of sitting
would help to mitigate the risk of
ingestion of contaminated matter as it
would not be so inviting to stop and
picnic for lunch.
More extreme examples include
applying ‗anti-sit measures‘ to other surfaces, just to make sure no-one stops in the
area. This is a very powerful tool, as remarked by Lockton and other bloggers, but
through judicious use could prove useful in reducing contact between users and some
‗less appropriate‘ areas of a landscape. The danger (in design terms) of employing such
measures is that rather than simply reminding or suggesting that a visitor moves on, the
message is strong enough or ugly enough to cause the visitor to be repelled by scheme
overall.
Figure 28 Decorative?
Figure 28 Aggressive?

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All parties at the summer seminar (EPA, 2010) reported there being a lack of innovative
and inspiring case studies to draw upon when promoting the concept of sustainable
remediation. Databases found largely focus on the technical strategies employed in the
removal of contamination. Here follow a small number of case studies where the role of
the Landscape Architect or skills they may have been able to contribute are evident.
In all the cases examined, the project teams have faced and overcome adversity from
decision making bodies regarding the suitability of approach after presenting pioneering
ideas about how we should demonstrate and celebrate the treatment of the
environment rather than conduct it behind hidden barriers as something shameful.
As the buildings characterise so many of the post industrial sites repurposed according to
a ‗renovation‘ model, reflecting upon the site as a palimpsest (Nakamura, 1988). So the
post-industrial remains found within the soil and water can be used to inform the
designs of such landscapes. A recurring theme amongst those working in the design of
post-industrial sites is that of the second law of thermodynamics. The reference is
basically down to the singular direction of times arrow (as defined by ever increasing net
entropy).
So inspired, each of the studies are individually presented in a chronological fashion.

49. Page | 40
The AMD & ART Project,
Pennsylvania, USA
Situated in the small town of Vintondale,
Pennsylvania, this public park of around 14 Hectares was completed in 2000 after six years of
work by an interdisciplinary team.
The park today (2010) courtesy of Bing aerial mapping
The town is located on the Appalachian Region Coal field, where unregulated tipping of mine
wastes for several decades resulted in widespread acid rock drainage throughout Pennsylvania
and surrounding states. The site, on the South Branch of Blacklick Creek, previously housed a
colliery which employed many of the residents
in the small town. But coal production in the
area ceased by the 1950's and three quarters of
the population have since left.
The creek was lined with 'yellow boy', the
complex precipitate which is typical of this
acid mine drainage (AMD) contamination, and
the land on the site comprised was left dirty
and abandoned. Described by T. Allen Comp as:
―A wasteland that neither honored [sic] the past nor created opportunities for
the future of the people‖ (AMD&ART, 2007)
Allen Comp, a Historian, directed the project team of artists and scientists which included the
Landscape Architect Julie Bargmann, who is now well known for designing such post-industrial
sites. A chain of treatment ponds were designed curling around the higher ground to the north
of the site. Over ten thousand native wetland plants were installed, on a bed of limestone
chippings in the upper ponds, used to raise the pH of the water passing through. Drawing
inspiration from the colour change observed as the metals precipitated back out of the water,
the terrestrial planting was chosen to echo this colour change in the autumn leaf colour.
 Public Consultation
and Involvement
 Rhizofiltration
Figure 29 Yellow boy (DIRT, 2007)

50. Page | 41
Figure 30 Masterplan (AMD+ART, 2007)
Access to the waterside is not
restricted by any barrier, although the
risk of entry into the water is reduced
through the rural location, local
knowledge of the project, and paths
being set back from the banks.
The site has a number of signs both at
the entrance, and around the ponds;
these serve to educate the visitors to
the processes and concept behind the
project, and in so doing inform them
of the hazards the water presents.
―We wanted a site that would engage any visitor at any time of day without staff
being required. Signage made that possible and we did our best to make it as art-
full as everything else on the site.‖(AMD&ART, 2007)
Figure 31 view down the treatment ponds (Levy,
2010)

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Figure 32 Sign in situ: warning and to educating about the function of the landscape
Figure 33 Sign to explain the artistic concept behind the landscape
This project epitomises this thesis, that good, strong design can be the key to creating
an accessible, inspiring, artistic and technological landscape. However, this very wide
ranging set of objectives made securing the funding no simple matter:
"For many years, I think we were seen as too artsy for the serious environmental
and science funders and too environmental for serious arts funders.‖ T. Allen
Comp (AMD&ART, 2007)

52. Page | 43
Landschaftspark, Duisburg Nord,
Germany
This project, by Latz + Partner, is widely cited and studied as a post-industrial
landscape, largely for its renovation philosophy and reuse of the onsite structures. A lot
less is found in the literature regarding the protective measures taken for, or the
resolution of the contamination, which is itself well documented (Latz, 2001).
The 230-hectare site previously housed the huge Thyssen steel mill and associated
buildings. Following its decommissioning, the project to redevelop the site was developed
in phases over the course of thirteen years, from 1989 to 2002 (Pirzio-Biroli, 2004).
The contamination across the site included localised areas of heavy metals
contamination, and extensive areas with poly-aromatic hydrocarbons (PAH) and
chlorinated hydrocarbons. As this is a very large and complex site, a number of
strategies have been employed to mitigate the effects of the contamination, from a
single area of ‗hot spot‘ removal (dig and dump), groundwater treatment with activated
carbon (pump and treat), capping and monitored natural attenuation (MNA) (Schrenk,
 Succession planned in
 Pathway Removal
 Pathway disruption

53. Page | 44
2007).
At the entrance to the park, there is a map of the site which bears a non-specific
warning about the potential hazards that may be found there owing to the previous
industrial use. Other use of signage includes alongside water bodies to prohibit wading
or swimming and on the high walkways to draw attention to the processes going on in
inaccessible spaces below
(Hemming, 2007).
The unusual chemical
contamination and years of
importing materials onto site have
resulted in the deposition of a
wide variety of native and exotic
seeds. Up to 450 species have been
identified amongst the early stages
of succession alone. (EDRA, 2008)
An area designated ‗the
wilderness‘ became relatively cut
off following the redesign of a
large highway junction nearby and
as such became particularly well developed with spontaneous vegetation. Its value as a
nature reserve was deemed greater than the
requirement to access that space and entry into
this area is now forbidden (Landschaftspark
Duisburg-Nord, 2010).
It is remarked that a large number of songbirds may
be found in this area and the flora includes common
elder shrubs, common hawthorn and willow trees
and blackberry bushes.
A blogger reports making blackberry jam on the
same day as visiting the park and given how prolific
the blackberries were said to have been at the park
on that day, it seems likely that this was their
source (Hemming, 2007). From this it is concluded that no precautionary measures are
taken to prevent or advise against consumption of the vegetation, and raises questions
Figure 35 (ayurvediccure, 2008)
Figure 34 The Wilderness (Spekking, 2006)

54. Page | 45
regarding the land use proposal used in any risk assessment model. It is reckoned that
PAH would accumulate in fruit such as blackberries, but in relatively low concentrations
posing little threat to human health when consumed in moderate quantities (Collins,
2000)(Samsøe-Petersen, 2002). What is makes this truly delightful in this is that a
member of the public, well aware of the site history (as a Landscape architect), has felt
comfortable enough in the landscape to take some home and to consume it.
In addition to the spontaneous vegetation, species that are particularly tolerant of the
ashy substrate the slag presents have been imported deliberately from as far afield as
South Africa, Brazil and Australia (Latz,
1996).
The Park has a complex network of
‗official‘ and spontaneous paths with
different surfaces. Most of the main
elements are universally accessible.
Colour is used to distinguish these main
paths; blue for touchable, and red for
earth of useable. Areas for which
access is discouraged are naturally left
to weather to shades grey and rusty.
(Latz, 1996). Large parts of the park,
are only experienced by following small
cow paths, enhancing the sense of
mystery and discovery. (Langhorst,
2009). The site of a former coking plant, now heavily contaminated with PAH and
described as being black waste material colonised by solitary groups of birches is
accessible. Whilst public access is permitted through this area, by some measures the
uses are restricted to walking and cycling (Latz, 2001)
.
Figure 36 Walkway over the Sinter Garden (Latz,
2010)

55. Page | 46
Figure 37 Bunker garden, much of it only visibly accessible from above (Latz, 2010). Signs direct the
viewer to the „Wumfarne‟ or worm ferns growing on the walls in the chambers below.
The extent of the contamination in the Emscher river has not been deemed treatable
within the area of the park and so the flow is carried through the site in a buried
culvert. The original basin of the Old Emscher is now filled only with rainwater which is
channelled off clean or capped surfaces in the park and undergoes wetlands treatment.
The exclusion of the hazardous water has meant that public access points have been
allowed for along the bank of the river including steps down into the water in places.
Figure 38 The separation of the Emscher (culverted under the path) from the rainwater canal.
(Landschaftspark, 2010)

56. Page | 47
Markham Willows,
Derbyshire, UK
Markham colliery was closed in 1993 and
after its purpose had been served the land
was left beneath several large slag heaps or
spoil tips. Derbyshire County Council
undertook to remediate the 106 Ha site and
construct a business and industrial park upon
a new junction of the M1.
The north tip had been
capped to some degree
with soil and grass
planted, however the pH
of the water across the
area is being lowered by
the oxidation of exposed
pyrites, causing the grass
to die off and the soil be
washed away. Left as
was, full reversion to a
grey spoil heap was
expected within a few
years. This was not
deemed suitable as a
backdrop to a new
business park, nor as a
landmark on the busy
motorway and so an
alternative solution was
sought.
 Economic benefits through
speed of consultation and
by maximising productive
land use
 Phytostabilization through
Short Rotation Coppice
(SRC)
 Detailed and public risk
assessment
Figure 39. Markham Vale Masterplan (Vector Design Concepts, 2010)

57. Page | 48
In addition to, and also caused by the presence of the acid mine
drainage (AMD), the pollutants of concern included a range of metals
and also dioxins.
For the purposes of risk assessment the end use ―Residential without
plant uptake‖ was used as commercial premises are not a distinct
category of use catered for in many risk assessment tools. This was
incorporated into the risk model to formulate Soil Guidance Values
for both warning and action levels. Centralised guidance was not
available for dioxins a level was proposed that posed an acceptable
risk except to ―certain infrequent vulnerable groups‖.
After initial measurements were taken across the site in 1999-2000, a
particular area on the southward face of the north tip was found to be too highly
contaminated for public
access and as such was laid
to deciduous woodland and
fenced off.
In a report published by
AEA Technology (2004a)
there is a brief mention of
the debate surrounding the
relative merits of the SRC
and the fenced woodland in
respect of the entire site:
―the greatest effect on
stabilizing
contaminants … …is likely
to be achieve through the
use of short rotation
coppice…‖
―Overall the greatest
protective effect is to
promote deciduous
woodland… and fence them
off to prevent public
access‖.
As such, large areas of the
site have now been put to
Figure 41 Detail of North tip (AEA Technology, 2004b)
Figure 40 Parent
skeleton of
'dioxins'

58. Page | 49
productive use. Sewerage sludge has been applied across the site to improve the organic
content of the substrate, this is in order to maximise growth of the willow, contributing
to the stabilisation and the economic benefits.
During the draft remediation strategy the sensitive receptors were identified as:
 Those using the bridal paths across site
 Those on other areas of the site – not bridal paths
 A number of nearby water courses.
Figure 42 Conceptual Model for Risk assessment (AEA Technology, 2004)
In all instances, the risk of acute exposure has been reduced by localised ‗hot spot‘
removal. No information has been gained about the fate of such removed material.
For those on the bridal paths, the primary concern was that of contact between the
users and the contamination within and upon the soil. The strategy here was to use
‗conventional cover‘ protected by a wearing surface.
Contact and absorption of contamination by terrestrial receptors, humans and animals
alike has been reduced through a strategy of employing SRC on areas of relatively

59. Page | 50
greater contamination and woods and meadow on all other areas.
Permeable reactive barriers (including bioscreens) and Monitored Natural Attenuation
are being considered for use if contamination levels are deemed to pose a threat to the
water courses after site specific assessment criteria have been applied.
By examining the relative merit of the various technologies, planting and access
strategies on each individual contaminated area, this project manages to finely balance
the risks to human health with the risk to the wider environment.
The planning discussions took place in the presence of the developer, the local County
Council and another ‗local regulator‘. Having such a scheme approved and implemented
within such a short time frame will undoubtedly have been to the economic benefit of
everyone involved.
It is promising to see this forward thinking and pragmatic view being taken in the
treatment of a large contaminated site in the UK.
A business review conducted very recently has remarked though that only 87 out of a
promised 5000 jobs have been created at the development (Parnell, 2010), and this has
been credited in part to the current economic conditions in the UK rather than the lack
of inspiring architecture demonstrated by the landmark environmental centre on site.
Figure 43 Markham Vale Environmental Centre

60. Page | 51
Victor Civita Plaza,
São Paulo, Brazil
At approximately
1.5 Ha, this is the
smallest of the
sites studied. The
plaza is located on
a plot previously
occupied by a
municipal
incinerator, where
for forty years
material including
hospital waste
underwent
destruction.
In 2001 when the
land had been
handed over for
the construction
of a new public
square, testing
found that the
soils on the site
was contaminated
with dioxins,
furans and heavy
metals including
lead, aluminium and zinc.
It was felt by the scientific team that there was no practical way of removing or
neutralising all of the contamination in one fell swoop and so for cost reasons they
determined to monitor the natural attenuation processes and undertake to allow
 Monitored Natural
Attenuation
 Pathway removal
Figure 44 Ground Plans Praca Victor Civitas (Dietszch, 2008)

61. Page | 52
protected access to the
site in the meantime.
Initially the authorities
determined that capping
the contaminated land
with approximately 50 cm
of fresh imported soil
would provide the best
barrier to access. Instead
the design team, led by
Anna Dietzsch and Adriana
Levisky demonstrated
much more imaginative
and architectural response to the brief. A hardwood deck has been constructed to bridge
over the contaminated land, preventing a risk being posed to the users.
Two areas did undergo this soil capping, one is an area under some existing mature trees
retained in one corner. Groundwater and soil sampling points have been established here
and public access to this area is not permitted although the means by which this
achieved are not known.
The other area in which the soil layer was applied is a flagstone square and children‘s
play area.
The planted areas alongside
the decking are referred to as
the tec-garden and the
planting has been inspired by
commodity crops grown in
Brazil. To moderate access to
the contaminated soil beneath,
all this planting is grown in
suspended trays which wick
water up from below, where
the surface water is used as a
capping layer and also allow for
some filtering type planting.
Figure 45 Section of platform (Dietszch, 2008)
Figure 46 Relationship of platforms to existing vegetation
(Dietszch, 2008)

62. Page | 53
Figure 48 Wetland and raised 'Tec garden'
platforms. In the background the platform bends up
and over to form a roofed structure in the centre of
the space. (Espinillar, 2010)
Figure 47 Tec Garden: as planned for the
Praca Victor Civita, and as presented as a
commercial product with Remaster
Technology (Dietszch, 2008, Abbud, 2010)