The eThekwini Municipality is an area of approximately 2 300 km2 and is bounded by the Indian Ocean to the east, Tongaat to the north and Umkomaas in the south. The western extent is Cato Ridge (Jackson, 2003).
To determine the incidence and mechanisms of LNAPL contamination within the eThekwini region, the following sources of information were analysed:
1. Data from the eThekwini Fire and Emergency Services database, Durban;
2. Data from Teleatlas; and
3. Site assessment data from a local consultancy7. Figure 8.1 illustrates a Venn Diagram of the above data.
Fire and Emergency Services Data (commercial and retail LNAPL sites in eThekwini)
All commercial and retail LNAPL sites in eThekwini, known and unknown
Teleatlas Data (retail sites in eThekwini)
Consultancy Data (Retail and commercial sites in eThekwini and outside
eThekwini)
Figure 8.1 Venn diagram illustrating data sources relative to commercial and retail LNAPL storage sites in eThekwini
Figure 8.1 illustrates the following information:
7 As specified in the Institute for Groundwater Studies Inception Report (Pretorius, et al, 2007)
The entire population of retail and commercial LNAPL storage sites in eThekwini. The number of sites is likely to have increased substantially considering that the municipal area has increased from 300 km2 to 2290 km2 between 1994 and current according to information published on the eThekwini Municipality web page (www.durban.gov.za).
The population of retail and commercial LNAPL storages sites in eThekwini known to the eThekwini Fire and Emergency Services.
The Teleatlas data subset of retail LNAPL storage sites in eThekwini.
The Consultancy data subset of retail and commercial LNAPL storage sites in eThekwini and outside eThekwini.
The following sections provide further details of the above data.
8.1 eThekwini Fire and Emergency Services data
The eThekwini Fire and Emergency Services are responsible for responding to fire related issues; as well as the routine inspection of commercial and industrial properties for compliance with SABS 0400: The Application of the National Building Regulations (SANS, 1990) and the Interim Code Relating to Fire Prevention and Flammable Liquids and Substances (Durban Metropolitan Council, undated). This includes, amongst other duties, the inspection of Certificates of Registration for flammable substances, inspection of the fuel storage facilities and inspection of fire fighting equipment.
Data from the above fieldwork are recorded by Fire Officers on Application Forms for Certificate of Registration and Fire Prevention Worksheets, examples of which are attached as Appendix C and Appendix D respectively.
Data are entered into the database by data clerks. In addition, the database includes any other building structure, including residential properties, that the Fire Department has visited as a result of a fire related matter.
Data was retrieved by a third party from the eThekwini Municipality Fire and Emergency Services database and entered into Microsoft Excel (primary database). The following items summarise the data:
The primary database contained 65 535 records; and
Records included all sites from alphabetical letter A to V (site name). Sites with alphabetical letter W to Z were missing.
The following initial fields were of interest, and were extracted from the primary database:
Name of sites that store Class 1, Class 2 or Class 3 products;
Site contact person;
Site address and telephone number;
Business occupancy classification (class of business);
Volume of each Class Product stored at each site; and
Date of plan approval and any other date indicating record entry.
A total of 1567 records were extracted and entered into a final database, however for the purposes of this study,
249 additional records were required to be included from the primary database.
360 records were removed from the final database.
Table 8.1 presents the criteria for data inclusion in the final database:
Table 8.1. Additional extraction criteria for eThekwini Fire and Emergency Services final database
DATA INCLUDED COMMENTS
Sites from within eThekwini The database included sites from outside of the eThekwini region (as per their name) and were thus excluded.
Sites that recorded Class 1, Class 2 or Class 3 product storage.
Class 0 excluded as this is Liquid Petroleum Gas (LPG)
A single entry per site. Site duplicates with same addresses were excluded.
Sites with volume storage > 2 000 L and
< 200 000 L.
This was performed in order to exclude small farm installations and bulk depot storage, including all sites within the Island View Cutler Complex and the Refineries.
Sites known to be service stations by description but with no recorded volume storage. This included sites with the following terms in the name:
Service Station Ultra City Filling Station BP
Caltex Engen Sasol Shell Total
Excluding oil company offices, gas stores and pipelines
DATA INCLUDED COMMENTS Sites known to be service stations by description
and with volume storage > 200 000 L.
Some retail sites store > 200 000 L.
Based on the above criteria, a total of 1456 records were extracted and utilised for data analysis.
Table 8.2 presents an example of a data entry in the eThekwini Fire and Emergency Services Database:
Table 8.2. Data entry example for eThekwini Fire and Emergency Services database Business Or
Company Name
Date Qty Class 1 \ Product Qty Class 3 \ Product First
Occupied
Approved Plans Approved ATHLONE
SERVICE STATION
not stated not stated not stated NIL 56 000 70 000 L NIL 14 000
Limitations of the data are as follows:
The data excludes sites that may store product but the volumes are not recorded;
The data does not distinguish between underground installations and above-ground installations;
The data includes sites that are known to have closed;
Sorting and correction involved necessary interpretation of data entered, including data entered into the wrong field, un-separated product volumes etc
The extracted data are attached as Appendix E: eThekwini Fire and Emergency Services Extracted Data.
Appendix F provides a key to the Occupancy Codes (SABS 0400, 1990).
8.2 Teleatlas data
Geographic Information System (GIS) data for the eThekwini Municipality was provided by Teleatlas in the form of a Shape File. Data was retrieved from the Shape File Attribute Table and consisted of the following information:
Oil company;
Site name; and
Site latitude and longitude co-ordinates.
Some sites were only listed as an oil company with no corresponding site name, while others were listed according to oil company and area of location. No records were removed or added.
8.3 Consultancy data
Data from a local engineering and environmental consultancy was retrieved. The consultancy offers services primarily to the oil industry and operates from all major centres within South Africa, serving the Southern Africa region. Assessment reports for service stations and commercial installations were reviewed for the period 1999 to 2009. A total of 229 reports were reviewed for sites from within the eThekwini Municipality and outside the Municipality. The following data fields were extracted:
Table 8.3. Fields extracted from consultancy data
DATA FIELD DESCRIPTION
Site ID Unique identification number per site
Durban / not Durban Site location: either within eThekwini region or outside Commercial or retail Classification of facility
Assessment year Year between 1999 and 2009
Age of installation The age of the equipment since installation Submersible or suction Pump system type
Contamination status of site Classification of contamination status of the site according to presence and / or occurrence of free phase product and / or soil contamination and / or dissolved phase groundwater contamination and / or contaminated potable water
Product of contamination Record of the product of contamination in the event of an incident
Volume of product lost Volume of product lost in litres, if known
Cause of contamination Classification of the cause of contamination, if contaminated
Reason for assessment Classification of the reason for assessment
Bias / No Bias Sites were classified according to whether the assessment was incident related or not. Incident related sites were considered to have introduced a bias into the data, while non-incident related assessments were considered an unbiased population group.
AST or UST Tank position, either underground, above-ground or semi- buried.
Tank type Description of the tank type: mild steel (MS), Glass Fibre Reinforced Polyester (GRP) or Double Walled
Line Type Description of line type (mild steel, non-ferrous single containment or non-ferrous dual containment)
Number of tanks Number of underground and aboveground horizontal storage tanks
The data, as well as data qualification and notes are attached as Appendix G.
The data was analysed according to the above data fields.
8.4 Regulatory assessment
In addition to the above, local and international regulatory structures were reviewed within the context of the literature and results in order to determine if sufficient legislative mechanisms are in place and whether additional structures are deemed to be required within the South African context. This included:
The role of municipal governance in areas where preventative measures could be enforced.
The establishment and maintenance of an effective tank database is discussed in order to manage infrastructure on a local level, and respond to incidents effectively and timeously.
The potential for the tank data to be extended onto a GIS platform whereby the information can be interfaced spatially.
The effectiveness of Environmental Impact Assessment regulations is discussed.
Areas of governance where improvements could be made.