This assignment concerns an outline application for the construction of new housing on an abandoned factory site (brownfield) located in the virtual town of Middlesex. It is conceived that the site will be laid out with a housing density of 20 to 50 dwellings per hectare, with the remaining space set to outdoor garden and play space. Being a fully qualified Environmental Health Practitioner (EHP) and acting on behalf of the local authority as an EHP, the main aims of this assignment for the Formative assessment are outlined below:
The Health implications of the site will be clearly assessed and explained. A Conceptual Model of the site (diagram) which clearly shows the linkages between the site and the potential uptake by the proposed residents will be produced. The general principles will be evaluated and appraised in relation to the chosen pollutant.
SITE SUMMARY
There is one major stream around the site which connects to the River Blur drainage system. It is currently used for water abstraction in a nearby food production plant. An Aquifer exists within the local sandstone, but this located at depth under Mercia Mudstone.
Directly underlying the site are Mercia Mudstones with seams of sand gypsum. There is very little growth in the areas nearer to the tankers, with signs of stress in vegetation on the embankment adjacent to the stream. There appear to be no risk of flooding to the site and it has a gradual slope towards the nearby stream. Currently, there is no protection against pollutants running off the site and directly into the local surface drainage system which discharges to the nearby stream. The soil pH is approximately 6.9. The previous use of the land was mainly based on pharmaceutical production involving the use of various a range of petroleum derivatives within production and as solvents.
The concentrations of various pollutants recorded in soil samples from the site, which have been compared to the standard Soil Guidance Values (SGVs) alongside the health implications are given below in Table 1.
Contaminant Soil
Ground Water
Health Implication
Chemicals Concentration Determined in soil
µg/g Optimum
mg/kg Threshold
mg/kg Concentration Determined in Water
µg/l Optimum
µg/l Threshold
µg/l
Cd 12 0.8 12 0.2 0.4 6 Kidney Damage
Ni
17
35
210
10
15
75 Cancer, Dramatis, Asthma
Phenol
160
0.05
40
40
0.2
2000 Cardiac and Respiratory effects, Skin inflammation
Benzene
2
0.05
2
4.5
0.2
30 Increased risk of cancer, Anaemia, Decreased blood platelets
Toluene
200
0.05
130
87
0.2
1000 Kidney, Liver or nerve problems
Ethylbenzene 87 0.05 50 25 0.2 150 Liver or kidney problems
Xylenes
56
0.05
25
10
0.2
70 Nervous system, liver or circulatory problems
Total Petroleum Hydrocarbons
˃C10-C14 400 50 500 300 _
1, 1,1 Trichloroethane 24 0.07 15 0.8 0.01 300 Nervous system damage
Table 1.
For a land or an area to be classified as contaminated land, it should have the tendency to cause significant harm or present significant capability of such harm to a receptor (Health Protection Agency (HPA),2009). According to the EC (2013) In-Depth Report on soil contamination, soil contaminants may be responsible for health problems from cancers (Benzene and Nickel), kidney damage (Cadmium) and bone and skeletal diseases (Cadmium) costing millions. The direct human intakes of soil contaminants are mainly through three routes: eating, inhalation and skin or dermal (EC, 2013), and indirectly from soils into ground or surface water which leads to contaminated drinking water. The contaminants may be taken up by plants and eventually eaten either by humans or livestock.
In Table 1, colour coding has been used to indicate which chemicals require immediate actions taken and which ones require long term and ones that are safe. The rows highlighted in red indicates that those chemicals are above the threshold point and requires immediate action to be taken. Green indicates chemicals are safe but might require some future checks to ensure they don’t increase. Finally, yellow indicates those that have reached the threshold point and requires actions taken. The values of the contaminants below the suitable SGV cannot be deemed not to present unacceptable risk to human health, whereas when the concentration levels are more than the SGV, it is probable the there is enough evidence for potentially unacceptable risk to human health to necessitate further considerations (Environmental Agency (EA), 2008).
CONCEPTUAL DESIGN
Diagram 1. Conceptual land Design
The current government policy promotes redevelopments of brownfield sites, of which UK is known to have large number of them (Russell et al, 2008). However, Russell et al (2008) reported that many of these brownfield sites are contaminated. Hence, it is essential to acknowledge that this will present ongoing health implications such that environmental protection procedures need to be applied to determine risk to public health (Health Protection Agency (HPA), 2009). As part of the preliminary risk assessment through which the environmental health practitioner aims to reduce the potential future harm, a conceptual model of the site is created showing the linkages between the site and the possible routes to the future residents (Department for Environment, Food & Rural Affairs and Environment Agency (DEFRA), 2016) as indicated in Table 2.
CONTAMINANT PATHWAY RECEPTORS LEGISLATION
Cd Ingestion, Inhalation and Dermal
Migration of aqueous and free-phase contaminants in groundwater and surface runoff Future residents, site workers and neighbours Environmental Protection Act 1990 Part 2A
Contaminated Land (England) Regulation 2006
Ni Ingestion, Inhalation and Dermal Future residents, neighbouring residents, and grazing animals Environmental Protection Act 1990 Part 2A
Contaminated Land (England) Regulation 2006
Phenol Ingestion, Inhalation and dermal. Groundwater, the stream in the major vicinity. The drainage system of river Blur. Future residents and neighbours. Environmental Protection Act 1990 Part 2A
Contaminated Land (England) Regulation 2006
Water Resources Act 1991
Benzene Inhalation, Ingestion, Dermal Site workers, Residents and neighbours Environmental Protection Act 1990 Part 2A
Toluene Ingestion, Dermal and Inhalation Future residents, Site workers and Environmental Protection Act 1990 Part 2A
Ethylbenzene Inhalation Residents, Site workers Environmental Protection Act 1990 Part 2A
Xylenes Ingestion, Inhalation and Ocular Site workers, Residents and Neighbours Environmental Protection Act 1990 Part 2A
Total Petroleum Hydrocarbons ˃C10-C14 Inhalation, Dermal and Ingestion Groundwater, Residents, Site workers. Environmental Protection Act 1990 Part 2A
1,1,1Trichloroethane Ingestion, Inhalation and Dermal Residents, site workers, Neighbours Environmental Protection Act 1990 Part 2A
Table 2.
CONCLUSION
The analyses and assessment of the conditions of the site from all indications shows that the land is contaminated, and it poses a sufficient risk of notable harm to the potential future residents and users of the land. It will be recommended that the permit only be granted on the basis that appropriate remediation is carried out on the land to eliminate or minimise the risks to a level that the site is safe for its intended use (Higgins, 2016).
Full details of the legislations to remove the waste in the land and technical means to remove the agents from the land will be given in the summative.