Land contamination, restoration and revegation by Hayley Hughes

LSC 305: FINAL 3RD YEAR REPORT

LAND CONTAMINATION, RESTORATION AND REVEGATION

Former Croda Site Kilnhurst Rotherham UNIVERSITY OF SHEFFIELD HAYLEY HUGHES - STUDENT NO: 090163917

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

ABSTRACT This report aims to cover the assessment, treatment, and after use of contaminated and derelict land; at the former Croda Bitumen Site (only entrance at Carsisle Street) in Kilnhurst, Rotherham. This is site highly contaminated; thus a range of expertise will be needed in the reclamation and restoration plan. However this report is still intended for all audiences â&#x20AC;&#x201C; technical reports are included in extract boxes. This report also includes a conceptual model of the site; a key tool in the analysis of the interactions (pathways) between sources and receptors.

METHODS A combination of methods were undertaken in the production of this report. Most notably desk study of historic and current information on the site; alongside a site visit and informative brief in March 2013. Policy documents, environmental analysis and conceptual model were also key tools in the finalisation of a restoration and redevelopment plan; a full list of references can be found at the end of this report. The restoration plan has been adapted from the current housing proposal proposed by Gleeson Homes.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

CONTENTS 2

PREFACE – Abstract and Methods

BACKGROUND INFORMATION Site Location Site History Planning Context

BASELINE CONDITIONS Current Status Topography Ground Conditions Water Quality Ecological Value

CONCEPTUAL TABULATED MODEL Sources Receptors Pathways

REMEDIATION AND MITIGATION Remediation Strategy

REDEVELOPMENT AND REVEGETATION Original Proposal Adapted Proposal

REFERENCES

LIST OF IMAGES AND INSERTS

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

BACKGROUND INFORMATION SITE LOCATION The site is located in Swinton (Kilnhurst, Rotherham), on a thin industrial fringe; sandwiched between the steep railway embankment of the ‘Rotherham to Doncaster and Wakefield railway lines’ (west boundary of site), and the ‘Sheffield and South Yorkshire Navigation Canal’ (east boundary of site). Beyond this lies residential housing (to the west), disconnected by the railways; and rough open land and meanders of the River Don on the other side of the canal (to the east). A damaged bridge connects with this adjacent designated green belt (predominantly agricultural land) in the East. The site has a number of public rights of way – however they are poorly connected and neglected.

FORMER CRODA SITE

Figure 1 : Local Context, and Immediate surroundings Site location map (showing public rights of way, waterways, and railway lines.)

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Figure 2: Site within surroundings; showing land uses

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

SITE HISTORY This site has suffered from extensive tipping and contamination ; industrial use (initially involving chemical activities) dates back to the mid 19th century. 1880’s- Site owned by Messrs, Mitchells and Ellison coal distillation and processing workers. This initial industrial use was fuelled by the need for coke; an essential fuel for steel production. Toxic waste products extracted from coke (and assumed to be on site) are Benzene and Xylene. 1892- During the reign of Don Chemical Works, the northern part of the site was predominantly used for the deposition of waste products; the southern section used for the process of materials and location of storage tanks. Materials and chemicals from this time are mainly unknown and could pose serious risks. 1920’s- Occupied by Yorkshire Tar Distillers, where large storage tanks covered the site. 1940’s – Creosote was then produced for c. 30 years. Tar production was replaced with petroleum production (in 1970) – a beneficial change in method resulting in the release of less harmful chemicals.

Figure 3: 1892 map with existence of the Don Chemical Works. 1975- The site changed hands to the most recent site operator; Croda Tar and Bitumen Works During these years vast experimentation occurred (relating to the tipping and processing of bitumen) where waste product polymers were added to the bitumen; increasing flexibility and its available uses and applications. However theses polymers are mostly unidentified. 1981- All tar distillation works ceased, producing bitumen only until its closure (1998). 1998- The site has lain since vacant and all of the buildings have since been demolished; however the land, and surrounding environment has remained blighted by contamination – a significant lasting effect from its industrial past.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Figure 4: Site Boundaries within a wider context showing site outline key archaeological sites, and conservation areas This site holds cultural and archealogical value due to its close proximity with a number of archealogical priorities - such as the canal and railway routes. The site itself is regarded a key site due to the presence of Former Don Chemical Works. The potential to identify previously unrecorded archaeological remains is highly likely in the SE corner of the site.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

PLANNING CONTEXT The statutory Development Plan for the site comprises of the Rotherham Unitary Development Plan (UDP, 1999); and the Regional Strategy (2008). The site is designated as an existing Business and Industrial Use and part Urban Greenspace; however the condition and quality of the current greenspace is poor and disconnected.

Policy ENV5 - designed to protect major areas of Urban Greenspace from inappropriate development. 5.1 – “‘Allocated Urban Greenspace’ recognises that, in exceptional circumstances, there maybe an over-riding justification for the development of land allocated as Urban Greenspace …“ - currently the affordable and council housing shortages ; outlined in policies HG1/2– 5.5- “… where there is alternative provision of equal community benefit and accessibility and where there will be no net loss to the locality. The accessibility of alternative facilities will not only be assessed in terms of just distance, but also 'physical barriers' such as the need to cross classified roads and railway lines.

Figure 5 : Dumped litter floating down S&SY Navigation Canal

Rotherham Unitary Development Plan (1999)

Changes in use for this site is also influenced by Policy EC1 (UDP, 1999) which states; “Land allocated on the Proposals Map for industrial and business uses will remain predominantly in industrial or business use.” However as the site is part ‘allocated urban greenspace’; the restoration of the site and waterways, and redevelopment to a naturalised housing and local is appropriate – as it could help restore the local environment – improving health for the ecosystem and community. Alongside improved access to the waterside (for residents and businesses), natural green areas; whilst relieving housing pressure and giving a boost to the local economy. Reconnecting greenspaces (through pathways) is key to sustainability and health – promoting walking- ; as promoted in Policy T7: Public rights of way.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham As this historically known to be highly contaminated; any development must be within the guidance of PPG23 (Planning and Pollution Control). Policy ENV4.4 states " Where land that maybe contaminated as a result of previous usesâ&#x20AC;?, it requires that full guidance and additional expert advice must be sought in the any development or remediation plans. The remediation plan in this document is derived from this guidance (PPG23); alongside Policies regarding control of pollution and contaminated land (ENV 3.7/4.4)

Figure 6 : Picture of disused bridge pathway on site; damaged and littered with needles and waste

SUMMARY OF POLICIES RELATING TO THIS SITE AND REDEVELOPMENT Policy EC1 - Land Uses Policy ENV3 - Borough Landscape Policy ENV2.3- Maintaining Character and Quality of the Environment Policy ENV3.1 - Development and the Environment Policy ENV3.7 - Control of Pollution Policy ENV4.4 - Contaminated Land Policy ENV5- Urban Greenspace Policy ENV5.1- Allocated Urban Greenspace Policy CR2.1 - Outdoor Playing Space Standards Policy T7- Public Rights of Way Planning Policy Statement 1: Delivering Sustainable Development (2005)

Planning and Climate Change (Supplement to PPS1) Planning Policy Statement 5: Planning for the Historic Environment (2010) Planning Policy Statement 9: Biodiversity and Geological Conservation (2005) Planning Policy Guidance 13: Transport (2011) Planning Policy Statement 23: Planning and Pollution Control (2004) Policy Statement 25: Planning and Flood Risk (2010) Policy HG1 Existing Housing Areas Policy HG2 Existing Housing Stock Policy HG4.3 Windfall Sites Policy HG5 The Residential Environment

Note: Policies in bold have been referred too in this brief policy review (above).

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

BASELINE CONDITIONS CURRENT STATUS The site itself is a disused and derelict former industrial site (except current site workers removing existing structures); that is considered to have no amenity value in its highly polluted condition. Most of the buildings, tanks and other above-ground structures have been demolished to ground level; although a small number of concrete structures remain on the South area, alongside temporary structures (e.g offices, toilets) for workers continuing to restore the site. The site has had problems with fly tipping and antisocial uses (and effects â&#x20AC;&#x201C; graffiti, vandalism damage and drugs paraphernalia).

NE raised due to placement of fill materials.

Tar seeping through the ground at various locations There are also lime tailing mounds, rubble mounds, concrete, soap metal and other unidentified materials at random locations. A number of water bodies are present across the site, ranging from small pools to one large water body

SW raised due to the presence of a sandstone outcrops

Figure 7 : Detail Map of existing structures and outline of the site

TOPOGRAPHY The topography of the site is generally flat (at 18-19m+ AOD), with raised areas in the northern and south western portions of the site. (Detailed site topography can be found in the conceptual models and appendix.)

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

GROUND CONDITIONS The ground condition is varied and a highly contaminated; for detailed information please refer to the detailed maps (below) and ‘Potential Contaminant’ section.

Overall summary Large areas of hard-standing are present (particularly on the South area and in the south portion of the North area); alongside foundations, basements, and tanks are present in some areas of the site. There are also areas of bare earth, scrub vegetation and piles of rubble are locally present. The site consists of between 0.5 and 2.0 m of Made Ground (consisting predominantly variously of silt, sand, gravel and general demolition rubble. Made Ground overlies between 1.0 m and 5.0 m of alluvial deposits (consisting mainly of fine to coarse sand and fine to coarse gravels.) Beneath the alluvial deposits, Carboniferous Middle Coal Measures (consisting of layers of mudstone, siltstone, seat earth and coal in sequences up to 1500 m in depth - rarely more than 15 m in thickness). The Coal Measures outcrop at the surface is weathered as sandstones and mudstones. The potential contaminants at the Croda site are mainly Heavy metals (such as arsenic, lead and copper), Volatile Organic Compounds (benzene, ethylbenzene and xylene) and Asbestos. This is of great concern due to the proximity of waterways, urban greenspace and public rights of way. NORTH SIDE • Zone 1: exhibits Made Ground up to circa 5.50m thick comprising a thin soil veneer over heterogeneous waste over reworked green clay contaminated with tar/oils over interbedded white lime slurry and black ashy tarry beds; • Zone 2: predominantly Made Ground within which exhibits a thin veneer of soil over a greywhite lime waste to a max. recorded depth of 4.80m bgl (WTP44), although the base of the fill was not proven in all locations; • Zone 3. this generally has the thinnest Made Ground (maximum recorded thickness of circa 2.00m) generally comprising gravelly clayey deposits with cobbles of sandstone. Solidified pitch is present at, or close to, ground surface in some parts. Hard-standing is present across part of the area.

Figure 8 : Zones in North side of site (Technical Extracts and Images by Sirius, 2011)

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham SOUTH SIDE

• Zone 3 - Buried concrete and brick structures were extensively present. Shallow made ground generally consisted of a loose black sandy gravel of ash and clinker containing large quantities of brick and concrete. This was underlain by firm green black re-worked clay. Several trial pits also exhibited viscous bitumen; • Zone 4 - Shallow made ground generally consisted of a loose, black sandy gravel of ash and clinker with brick, pitch, wood and bitumen inclusions. Several trial pits exhibited soft white lime to a maximum recorded depth of 1.2m. Deeper made ground generally comprised a soft to firm orange brown re-worked clay, recorded to a maximum depth of 3.0m bgl;

Figure 9 : Zones in South side of site • Zone 1 - Made ground in this area generally consists of loose sand and gravel of ash and sandstone with brick and concrete, with, firm orange brown reworked clay with coal and brick fragments at depth. Thickness varied from 1.3m to 2.5m; • Zone 2 - Made ground generally consists of a loose black sandy gravel of ash and clinker with brick, concrete, wood, and metal inclusions to a maximum recorded depth of 1.90m. Underlying the ash and clinker was a thick layer of soft, light to dark grey lime with a strong odour. The maximum thickness of lime detected was 4.0m;

• Zone 5 The presence of concrete bases, sub-structure brick walls and services severely limited the locations and depths of exploratory excavations but, where investigation was possible, shallow made ground generally consisted of loose, black sandy gravel of ash and clinker with brick and concrete inclusions to a maximum recorded depth of 2.0m. Underlying this was soft grey green re-worked clay that was heavily stained.

Technical Extracts and Images by Sirius (2011)

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

WATER QUALITY The site is at key threat to local waterways (due to its close proximity to the River Don and S&SY canal). There is one larger water body on the (northern part of the site c. - 30mx 20m); its extent in the winter month’s is reported as ‘small shallow ephemeral water bodies’ (Sirius, 2011). One or two poorly draining marshy grassland areas have been reported; (in the north) during the winter months. Groundwater has been identified beneath the site predominantly within the alluvial deposits at a depth of approximately 4.5 m below ground level. Alluvial deposits are considered to be a minor aquifer of variable permeability. Coal Measures on site are considered to represent a minor aquifer of variable permeability; Made Ground is considered to be a non-aquifer. Water quality is of serious concern; as the site has been found to have contaminated local sand and gravel aquifers. The site is also at risk of contaminating the local waterways; which are highly important to local wildlife and overall ecosystem health.

TECHNICAL EXTRACT ON WATER CONTAMINATION “Hydrocarbons including elevated concentrations TPH, BTEX, PAHs (principally naphthalene) and phenolics have been found to be the most widespread contaminants of concern within the perched trial pit groundwater at the site during previous phases of investigation. Similarly, these contaminants, at significant concentrations, have been identified locally within the boreholes screened into the underlying shallow sand and gravel aquifer.” (Sirius, 2011)

Level and Records of Contaminants

Figure 11 : Contaminant concentrations in Perched Water N.B Perched water contaminants also leach into soils/ ground.

Figure 10 : Contaminant concentrations in Shallow Groundwater

- Aromatic contaminants (listed in fig - ) are compound derivitives of Beneze; some of which are grouped under the name Ethylbenzene.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

ECOLOGICAL AND LANDSCAPE VALUE The site currently has little ecological value (due to pollution); and detrimental landscape value (as it disconnects the local community from the waterways â&#x20AC;&#x201C; and damages it - ). However due to its location, it is considered to be of high potential ecological value (due to its close proximity with Greenbelt; and ecological connectivity from habitat continuity (due to two waterways and the linear railway vegetation). Flora The site is predominantly hardstanding or contaminated thin soils with a thin veneer of scrub on the surface; Ephemeral, short perennial vegetation, encroaching scrub characterises much of the site. Several areas of the site contain patches of species poor semi improved grass land; and some parts tall ruderal vegetation (over disturbed ground) which may provide some value to invertebrates. The railway embankment is heavily vegetated with a diversity in species and ecotones; ie. fairly dense scrub, trees, herb layer, woodland edge. Fauna Little is recorded for fauna in studies from the last ten years. Although bats were detected emerging from the Carlisle Street Bridge in 2005; although recent study reports loss of bat roost in the masonry face of the bridge. No rare or scarce bird species have been detected on the site, however it could have high value due to its connectivity. Little is known on its current ecological value of the sites waterways; however they have been known to support populations of smooth newt â&#x20AC;&#x201C; although no Great Crested Newts Ecosystem value This site poses highly detrimental risks to the ecosystem; especially due to its high connectivity (air quality, water quality, vehicle/train movement of dangerous particles, linear vegetative pathways) creating key threats for movement of contaminants/pollution, invasive species, disease, bacteria or pests. Landscape value Currently poor due to lack of connectivity and pollution. Could be of high value; due to improved access to the riverside (key connectivity), amongst a diversity of local priority habitats. Both will work in unison to provide a healthier environment, promoting walking and enjoyment of nature. Alongside fighting against site specific threats eg. tackling air and water pollution (bio-remediation methods e.g trees and reed beds) and pluvial flood risks via water run-off retention â&#x20AC;&#x201C; SUDS.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

CONCEPTUAL TABULATED MODEL The potential impact that the site's former uses may have on any proposed development on this site has been illustrated in a tabulated model; conceptualised into three main categories (sources, pathways and receptors).

PATHWAYS: Dermal or Ingestion contact with hazardous material poses serious risks to nearly all life forms. Serious risk for humans; particularly unsuspecting children or trespassers â&#x20AC;&#x201C; and wildlife.

Migration through soil or water Poses key threats to local water and soils; the basis for the whole ecosystem.

Inhalation/ Movement through air Intake via transported vapours or dust is a serious risk due to the trains and rivers increasing air flow; remediation will have to be careful to control the release of contaminants â&#x20AC;&#x201C; excavation increases vapour and dust release.

Local linear pathways The waterways and train lines are key risk pathways as they are at a close proximity to the site and both have great power to carry contaminants further afield.

Underground Services Any damages to the water or electricity works could be a serious threat to an unknown amount of people and businesses.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

SOURCES: Potential hazardous material details are outlined in the profiles below. Volatile Organic Compounds Mainly comprising of Benzene, Toluene, Ethylbenzene and Xylene; a dangerous group petrochemical compounds, referred to as ‘BTEX’. They are used in a number of industrial products/processes; also commonly occurring together as a result of polluted environment. They will all be present where coking operations took place (mainly north area, central zone, and south area – contamination widespread and affecting most made ground. Shallow ground-water beneath made ground. Also in Perch water, made ground, Soil, shallow sand/gravel, lime slurry, tar pits and underground storage tanks.;

Benzene (VOC) found alongside Tar (S-VOC) Systematic Name: cyclohexa-1,3,5-triene Other Names: 1,3,5-cyclohexatriene, benzol, phene

Description: Colourless liquid which evaporates rapidly in the air. Benzene is a natural constituent of crude oil, and is one of the most basic petrochemicals. Most non-industrial applications have been limited by benzene's carcinogenicity. Sources identification: - History of coke use: would be stripped out of base tar. - identified lime slurry and tar deposits – most likely also affecting soil and shallow sand and gravel clinkers. - Recorded concentrations from boreholes within the screened made ground. - identified water contamination. Key threats: Highly toxic to humans - releases toxic chemicals (ring chain molecules BTEX) identified as having contaminated water on site; also known as hydrocarbons – a carcinogenic. Dangerous substance that volatises rapidly from surface soil . Can cause explosions; this risk needs to be mitigated via a method of ‘burning off’ excess vapours. Notes: Reports have identified tar seeping out the ground at various locations. As a whole substance, tar is regarded only as a Semi-VOC; however these areas host a serious threat to the site. - Also contained in sealants, solvents, gripta, creosote - Real concern and key remediation risk as highly mobile through both ground and water; barrier methods to attempt to mitigate this risk by breaking pathways will be recommended in remediation.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Toluene (VOC) Systematic Name: Methylbenzene Other Names: formerly known as â&#x20AC;&#x2DC;toluolâ&#x20AC;&#x2122;. Also phenylmethane and Anisen.

Description: A colourless liquid that smells similar to gasoline with a sweet aroma; evaporates quickly and is highly flammable. It is a mono-substituted benzene derivative with the formula C6H5CH2CH3. Sources identification: - Industrial uses of toluene include dealkylation to benzene, and the disproportionation to a mixture of benzene and xylene. When oxidized it yields benzaldehyde and benzoic acid, two important intermediates in industrial chemistry. Also, commonly resultant from general pollution (degraditive compound on many industrial products) - Recorded concentrations from boreholes within the screened made ground. - Water contamination records. Key threats: Serious health threat - Toluene should not be inhaled; Low to moderate levels can cause tiredness, confusion, weakness, drunken-type actions, memory loss, nausea, loss of appetite, and hearing and colour vision loss. Symptoms usually disappear when exposure is stopped. Inhaling high levels of toluene in a short time may cause light-headedness, nausea, or sleepiness and even death. Notes: Toluene is, however, much less toxic than benzene - commonly replaced as an aromatic solvent in chemical preparation. For example, benzene is a known carcinogen, where as toluene has very little carcinogenic potential comparatively.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Ethylbenzene (VOC) Systematic Name: Ethylbenzene Other Names: Ethylbenzol; phenylethane, alpha-methyltoluene

Description: highly flammable, colourless liquid with an odour similar to that of gasoline. Monocyclic aromatic hydrocarbon is important in the petrochemical industry; produced on-site in the fractionation of crude oil and experimentation with the production and processing of styrene or mixed xylenes – poor practice - . Also a common derivative of degrading hydrocarbon compounds found in polluted places. Sources identification: - History of fractionation of crude oil and xylene experiments. - Recorded concentrations from boreholes within the screened made ground. - identified water contamination. Key threats: The longer term toxicity and carcinogenicity is unknown; lethal dose is about 4 grams per kilogram of body weight. Eye and throat sensitivity and dizziness, can occur when high level exposure to ethylbenzene in the air occurs. Ethylbenzene is found mostly as a vapour in the air since it can easily move from water and soil. Can cause explosions; this risk needs to be mitigated via a method of ‘burning off’ excess vapours. Notes: Luckily the volatility of Ethylbenzene is reduced when other hydro carbons are present; it is also only moderately mobile in the soil. Compared with other compounds, this one has a lower aqueous solubility and tends to collect at the water table; however this still poses a key risk due to proximity with the environmentally valuable canal and Don.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Xylene Systematic Name: A number of aromatic isomer compounds which fit this group

Description: an aromatic hydrocarbon consisting of a benzene ring with two methyl substituents. The three isomeric xylenes each have a molecular formula of C8H10; the semi-structural formula C6H4(CH3)2 is also commonly used and found (in industrial sites). The xylenes are major petrochemicals, produced by coal carbonisation in the manufacture of coke fuel; representing about 0.5–1% of crude oil. Sources identification: - Site history and general contamination found. - most likely also affecting most made ground, soil and shallow sand and gravel clinkers. - Recorded concentrations from boreholes within the screened made ground. - identified water contamination. Key threats: Highly toxic to humans, also a carcinogenic as radiates Toxic chemicals (ring chain molecules BTEX – hydrocarbons-) that can be transported for relatively long distances in (air, soil, water and physical contamination movement – shoes, vehicles/trains) . Notes: - Real threat to surrounding area; and key remediation risk as highly mobile through environment - both ground and water; barrier methods to attempt to mitigate this risk by breaking pathways will be recommended in remediation. These isomers are small chain polymers which have joined to make larger polymers – thus generally occurring as a result of pollution.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

HEAVY METALS The presence of these metals results from the old buildings on site, and in machinery and tankers used in production processes; most commonly found in the southeast of the south side of the site. The most heavily polluted areas are likely to be in around old building foundations and tabulated process areas. Solubility of metals may increase under acidic conditions – a key threat due to the waterways and the presence of acidity causing Arsenic.

Copper Symbol: Cu Atomic No: 29 Atomic Mass: 63.546 ± 0.003 u Description: Pure copper is soft and malleable; a freshly exposed surface has a reddishorange colour - with rust and green oxidisation over time. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal alloys. Sources Identified: Historical use and site reports (Sirius 2011, and desk research). Present in bog ore from coal process machines; and oxidised in lime tailing pits. Key Threats: Toxic/ phyto-toxic metal but a lesser threat than the previous heavy metals described. Poses a risk to humans (and ecology) on ingestion or through rust poising of Tetanus.

Arsenic Symbol: As Atomic No: 33 Atomic Mass: 74.9216 ± 0.00002 u Description: Arsenic occurs in many minerals, usually in conjunction with sulphur and metals, and also as a pure elemental crystal. The three most common arsenic allotropes are metallic grey, yellow and black arsenic, with grey being the most common. Sources Identified: Historical use and site reports (Sirius 2011, and desk research) Key Threats: Highly toxic to humans; Occupational exposure and arsenic poisoning historically occurred in persons working in industries involving the use of inorganic arsenic and its compounds. Long-term exposure to arsenic has been linked to bladder and kidney cancer in addition to cancer of the liver, prostate, skin, lungs, and nasal cavity Notes: Arsenic forms colourless, odourless, crystalline oxides As2O3 ("white arsenic") and As2O5, which are hygroscopic; readily soluble in water; causing acidic -ecologically damaging- solutions. Highly mobile in water; also influencing other metals to become more soluble.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

Lead Symbol: Pb Atomic No: 82 Atomic Mass: 207.2 Âą 0.1 u Description: Lead is a soft and malleable metal, which is regarded as a heavy metal and poor metal. It tarnishes to a dull greyish colour when exposed to air. Sources Identified: Historical use and site reports (Sirius 2011, and desk research) Key Threats: Highly poisonous metal to animals and humans; damages the nervous system and causes brain disorders and blood disorders in mammals. Notes: Its four stable isotopes have 82 protons- a magic number in the nuclear shell model of atomic nuclei- making it more stable than other configurations.

OTHER KNOWN POTENTIAL SOURCES/HAZARDS - Additional hazards All of the sites long history has created a number of un-known variables concerning polymers, chemicals and waste products. Unknown â&#x20AC;&#x201C; most likely high risk. General known hazards exist ie. sharp or rusty materials, abandoned needles, smashed glass and unknown contents of fly tipping. - Asbestos - Ammonia - Chromium - Phenol - Sulphate - Naphthalene - Tar pits - Lime tailing mounds - Water contaminants (Hydrocarbons) BTEX, PAHs (principally naphthalene) and phenolics

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

RECEPTORS: RECIEVERS OF ANY EFFECTS OF THE SITE The site has no International, National, Regional, County or Borough receptors; the site is fairly contained to local and neighbourhood receptors. However care needs to be taken to minimise the risk to pathways, accessing the wider area (waterways and train embankments); by carefully monitoring the environment for pollutants. The following list outlines the local site receptors of the hazardous sources: - Physical geology including geomorphology and palaeontology. Most likely damaged and will require expertise and time to restore. Geological bodies susceptible to impact from site contamination comprise shallow made ground, alluvial strata and coal measures strata below and adjacent to the site. The alluvial strata is of historic relevance, and therefore considered to be of local significance - the historic floodplain of the River Don. The shallow coal measures are also considered to be of local importance. - Water The River Don and S&SY canal are at serious risk - the latter more so due to proximity. Above ground fresh waters, ground water and alluvial deposits are also at risk of contamination. - Amenity and aesthetic landscape quality including impacts on those entering the site (health risks of hazardous materials), adjacent public footpaths/open space, nearby properties and there users/occupants (e.g. risks for individuals visiting the local green in the area directly adjacent to the site/ walkers on the canal side) - connectivity also currently suffers. - Local Residents / People Residents (or people) nearby are susceptible to vapours or contaminants swept up by winds or train movement (the extent of this risk is unknown). Residents entering or exploring the boundaries (in its current state) will most likely be at serious risk.

-Wildlife and vegetation Any post-industrial value in vegetation is mostly lost. Local wildlife is currently limited; bats and newts have been noted as present in recent years. Specific plans to aid their establishment in the development must be made. Restoring the waterways and local landscape will allow for a wide range of birds, mammals, invertebrates and amphibious creatures; improving the waterways will accommodate fish and aquatic wildlife (possibly allowing angling in the long term). - Overall Ecosystem (especially air quality) The ecosystem is currently at great risk both on a local and wider context; the site currently severely degrades the local system. Site remediation would improve water, air and soil quality; in term giving opportunity to a diversity of species and habitats â&#x20AC;&#x201C; creating a healthier and more resilient ecosystem.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

RESTORATION AND REMEDIATION Remediation techniques must be carried out prior to the new housing development (in order to restore the landscape and waterways - mitigating against any risks). This plan aims to remove sources of contamination or break pathways to receptors. The main target areas are soil, water and vegetation. The proposed remediation is based on the integrated application of complementary techniques (implemented by skilled experts). A key objective of remediation is to retain all suitable materials for on-site reuse (reducing off-site disposal and the requirement for import via vehicle or water movements). Planning summary is for a “Full planning application for the restoration and remediation of the site, including removal of relic structures and foundations, which will involve the temporary importation of material by road, and construction of development platforms to facilitate residential development and provision of public open space.” (Sirius Geotechnical & Environmental Ltd, 2011)

REMEDIATION STRATEGY NATURAL ATTENUATION MONITORING - A programme of natural attenuation monitoring – soil and water- (scope will be subject to agreement with the EA) is proposed before, during remediation works and for a period after the completion. This will set a precedent for the management of residual contamination in on and/or off-site soil and groundwater. PRE-REMEDIATION - Site clearances of remaining above-ground structures, and redundant drains (possibly grouted up – although recommendation for removal and reuse or disposal of all geotechnically unsuitable materials within the Made Ground ( demolition rubble, timber, pipework, drums, and buried structures e.g. relic foundations and slab). Excavation often destroys the native ecosystems (of which this site provides little contribution – more so significant detriment); and may expose workers and nearby residents to elevated levels of contaminants. However the solidification- stabilisation approach often cannot remove all contamination from the site, (NRC, 2000). Balancing complementary methods alongside expert advice is essential in correctly restoring the site. -All materials that can be made suitable for use through onsite treatment or remediation (e.g. concrete and rubble will be segregated and crushed/screen to allow reuse in green roofing projects and infilling of ground/retaining features); will be retained on site for use.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

SOIL REMEDIATION - Contaminated soils with the potential to pose risks to on and/or off-site receptors (ie via contaminant migration in shallow groundwater, or whose geotechnical properties require improvement to allow construction); will be subject to solidification-stabilisation by in situ or ex situ methods. - Solidification-stabilisation (a well-established remediation technique in which a customised blend of additives - generally including cement or lime) is mixed into the soil to bind and encapsulate mobile contaminants; thus reducing their rate of soil migration and achieving geotechnical properties; (please note this is not an effective method for areas suffering from lime problems already – additional expert advice will need to be sought) - The entire site will then be capped with a full, engineered capping layer (total thickness 1.1m) – with a design life of 250 years (Environment Agency, 2013); which will provide stability and structure to the ground whilst blocking a major pathway (protecting the development from any contamination). This layer is based upon a self- sealing low permeability geocomposite-clay liner (GCL); overlain by an engineered series of protective soil layers - including a “no dig” protective layer for utility corridors (at the interface between the engineered cap and overlying soils or structural materials)-. The benefits of GCL are that it is easily installed, achieves a very low permeability, and is able to self-heal in the event of minor damage or if penetrated. The capping layer will be overlaid by hardstanding or, in garden and landscaped areas, placed sub- and topsoil. CASE STUDY: ‘One of the most polluted landscapes in Europe’ restored through similar methods of soil excavation and removal to landfill ; alongside soil stabiliation and capping.

Figure 12: Orgreave colliery and Coke Plant c.1980

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

WATER REMEDIATION - Perched groundwater encountered during ground works and other identified areas of contaminated perched water; will be subject to removal (by multi-phase extraction). Vapour streams arising from the multi-phase extraction process that could be significantly contaminated with VOCs will be treated prior to dispatch. Free-phase product will be separated and sent to off-site recovery. - Recovered groundwater will be routed to a temporary water treatment unit prior to discharge, under permit, to foul sewer or other authorised outlet.

VEGETATION REMEDIATION Ecological restoration experts will be consulted on the final detail design for redevelopment of the site; ensuring the site is equipped with a diversity of interconnected green spaces (of varying habitats, and size). This will aid both human and wildlife populations in a number of ways. This remediation aims to restore priority habitats highlighted in the Doncaster Biodiversity Action Plan, as local to the site and waterways. Habitat types include: • Ancient and species rich hedgerows • Arable field margins • Crags, caves and tunnels • Greenways • Limestone grassland • Limestone woodland • Lowland heathland/acid grassland mosaic • Lowland heathy oak woodland • Lowland raised mire • Marshes and swamps, lakes and E ponds, ditches and drains • Minor streams, springs, fens, flushes, mires and fenny fields • Neutral and wet grassland • Parkland, wood pasture and veteran trees • Post industrial and brownfield land • Reedbeds • Rivers, canals, oxbows, major streams and subsidence flashes • Urban greenspace • Wet woodland

Note – Habitats highlighted in bold are present in the improved redevelopment design

Figure 13 : Post-industrial and brownfield landscape on site Should be accommodated in redevelopment via Retention of screened site substrates for use in green roof

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

March, 2011

METHODS OF SITE WASTE REMOVAL - Small amounts of unsuitable materials, will be removed from site using return trips of vehicles importing materials; and will therefore not increase the total vehicle movements â&#x20AC;&#x201C; to help mitigate the added disruption to the local residents. - Larger shipments of waste or hazardous material will be transported via the S&SY Canal way to the landfill site at Cadeby, (as advised by the EA, 2011).

Figure 14 : Route from site to landfill in Cadeby

Figure 15 : Community greenspace adjacent to the only vehicle entrance to the site

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

REDEVELOPMENT AND REVEGETATION ORIGINAL PROPOSAL The following restoration plans have been submitted by the ‘Woodford’ group (2011). The proposal has some weaknesses that could be addressed; in order to improve the redevelopment and its legacy. Please see insert for design plan of the original proposal.

Original Planning application ‘Woodford’ group: “Outline planning application for the erection of 381 dwellings (29571sq m / 318,305 sq ft gross); construction of access roads onto Carlisle Street, footpaths, car parking, drainage solutions, areas of open space and landscaping and associated works.” Additional Notes: - Lack of open green space (only 6092sqm); which is mostly borrowed from the surrounding with no plans to ecologically restore and landscape. - Lack of revegetation, and connectivity; which would significantly improve living conditions and the local environment. - Communities more dependent on cars (lack of amenities or public transport); due to pressured backfilling developments - into greenbelt land or other use - with little existing infrastructure. - Large increase to population with little connectivity and lack of community facilities.

Figure 16 : Original Development Proposal

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

IMPROVED DEVELOPMENT The adapted redevelopment aims to provide a healthier living environment for residents, and wider benefits for the local community. Adapted Planning application ‘Woodford’ group: “Outline planning application for the erection of 250 dwellings, 10 multifunctional additional business/ community/ residential buildings; construction of access roads onto Carlisle Street, footpaths, car parking, sustainable urban drainage solutions, large areas of interconnected open-space, landscaping (with ecological restoration expertise), restored waterways, community facilities (ie. Play equipment, small shop/ pub/ restaurant area on the riverside/ community centre) Additional Notes: - Onus on open green space, and ecological restoration (revegetation); which would significantly improve living conditions and the local environment. - Significant improvement to amenities and community facilities. - Improvements to connectivity within the development, with the wider community, and local landscapes (waterways and greenspace).

Figure 17 : Improved spatial quality in improved design; diversity, size, quality, connectivity and hierarchy.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

CONCLUSION The former Croda site is highly contaminated and poses a serious threat to a number of receptors. Remediation and redevelopment is essential and most likely tricky – involving the cooperation and decision making of a number of experts. The redevelopment strategy aims to create a healthier environment for individuals – after the sites polluted past. On a whole well connected green-spaces aid our wildlife and environment (quality of air, soil, water and living environment). Numerous studies have found that open green space can also have a beneficial impact on both the community’s and the individual’s wellbeing; natural views provide relaxation, increased happiness and reduced stress (Ulrich et al, 1991). Urban green spaces users have been proven to have longer longevity (Takano et al, 2002), and better physical, social and psychological health (van Kamp et al, 2003); most likely as they invoke lowered blood pressure and reduced mental fatigue (Kuo, 2001). The adapted plans also promote connectivity into the wider environment and provide community amenities – promoting walking, exercise- and business at a micro level; thus creating sustainable places which are less dependent on car use. These ecologically restoration adaptations have made a significant impact on the proposed remediation and redevelopment.

Figure 18: Detail of central route from railway bridge to canal/ houses, businesses or greenspaces.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

REFERENCES - Andel, J. van & Aronson, J. 2006. Restoration ecology. The new frontier. Blackwell, Oxford. DOE 1996. Reclamation of damaged land for nature conservation. HMSO,London. - DEFRA (2012) Contaminated Land. Found http://www.defra.gov.uk/environment/quality/land/. Last Accessed 16/04/2013 - The Don Network (2013); our plan for the river Don. Key stakeholder strategy document - Environment Agency, 2013; Guidance for the Safe Development of Housing on Land Affected by Contamination. R&D Publication 66: 2008 Volume 1. Found at: http://publications.environmentagency.gov.uk/pdf/SR-DPUB66-e-e.pdf. Last accessed 16/04/2013. - Environment Agency. (2013). Healthier environment; better fishing. Available: http://cdn.environment-agency.gov.uk/geho1006blak-e-e.pdf. Last accessed 6th April. - Eriksson,G ;Rasmuson,A ; Theliander, H. (1996). Displacement washing of lime mud: tailing effects. Available: http://www.sciencedirect.com/science/article/pii/0956961896001543. Last accessed 16th April 2013. - Jochimsen, M. E. 2001. Vegetation development and species assemblages in a long-term reclamation project on mine spoil. Ecological Engineering 17, 187-198. - Kuo, 2001; Coping with poverty: impacts of environment and attention in the inner city. - Planning Policy Guidance Notes & Statements can be sourced from www.gov.uk/planning. - National Academies Press (NAS). (2000). Natural Attenuation and Groundwater Restoration: Using Natural Processes in Groundwater Contamination. Commission on Geosciences, Environment and Resources. - (1), . - National Lime Association, USA. (2004). LIME-TREATED SOIL CONSTRUCTION MANUAL LIME STABILIZATION & LIME MODIFICATION . Available: http://www.graymont.com/technical/Lime_Treated_Soil_Construction_Manual.pdf. Last accessed 16th April 2013. - N Angelopoulos et al. (Publication date unknown). Flood risk management of an urban river â&#x20AC;&#x201C; riverine mitigation methods and implications for fisheries. Available: - Rivett, M. O., J. Petts, B. Butler & I. Martin 2002. Remediation of contaminated land and groundwater: experience in England and Wales. Journal of Environmental Management 65, 251268 - Takano et al. , 2002. Urban residential environments and longevity in mega-city areas; the importance of walkable greenspace. Journal of Epidemiology; community and health. - Todd, J., Brown, E. J. G. & Wells, E. 2003. Ecological design applied. Ecological Engineering 20, 421-440. - Ulrich et al, 1991. Stress recovery during exposure to natural and urban environments; Journal of environmental psychology - Sirius, 2011; A number of reports submitted for the planning application of the site. Found at www.roam.rotherham.gov.uk/.../. Consisted of Design and Access Statement (and Masterplan and contours found in appendix), Environmental Statement, Canal and Waterways Assessment, Ecological Assessment, Geology and ground conditions, Geotechnical assessment.

LSC 305 Report: Land Contamination, Restoration and Revegetation Former Croda Site, Kilnhurst, Rotherham

LIST OF IMAGES FIGURES Figure 1 : Local Context, and Immediate surroundings Site location map (showing public rights of way, waterways, and railway lines.) Figure 2: Site within surroundings; showing land uses Figure 3: 1892 map with existence of the Don Chemical Works. Figure 4: Site Boundaries within a wider context showing site outline key archaeological sites, and conservation areas Figure 5 : Dumped litter floating down S&SY Navigation Canal Figure 6 : Picture of disused bridge pathway on site; damaged and littered with needles and waste Figure 7 : Detail Map of existing structures and outline of the site Figure 8 : Zones in North side of site Figure 9 : Zones in South side of site Figure 10 : Contaminant concentrations in Shallow Groundwater Figure 11 : Contaminant concentrations in Perched Water Figure 12: Orgreave colliery and Coke Plant c.1980 Figure 13 : Post-industrial and brownfield landscape on site Figure 14 : Route from site to landfill in Cadeby Figure 15 : Community greenspace adjacent to the only vehicle entrance to the site Figure 16 :Original DevelopmentProposal Figure 17 : Improved spatial quality in improved design; diversity, size, quality, connectivity and hierarchy. Figure 18: Detail of central route from railway bridge to canal/ houses, businesses or greenspaces.

INSERTS 1 â&#x20AC;&#x201C;Macro Conceptual Tabulated Model 2 â&#x20AC;&#x201C;Micro Conceptual Tabulated Model 3- Original Redevelopment Masterplan 4- Adapted Redevelopment Masterplan 5- Detail Desgn 6- Comparative Sections 7- Conceptual comparison of connectivity and open greenspace 8- Site Contours