Former gasworks sites present substantial problems with ground contamination. The nature of the processes involved in the production of coal gas created a number of noxious by products which can persist in the soil.
Coal Tar may be found in the ground around buildings, condensers, scrubbers/washers, tar wells/tanks and the pipes connecting these. Coal tar may also be found in the base of tar tanks and gasholders. A number of potential components of coal tar are of concern
Ammoniacal Liquors were removed in the hydraulic main, foul main and condensers and also produced by spraying the gas with water in the washers and scrubbers.
Blue Billy, Foul Lime and Spent Oxide were all wastes of the gas purification process which would remove sulphur, cyanide and organic sulphur compounds from the gas.
Clearly it is essential to clear such contamination before developing a former gasworks, but undertaking such work is expensive, even more so when in close proximity (or within) historic buildings which by preference will be retained. The cost of such removal must be borne by the developer. If the cost of treatment to allow development is too high the only option is to leave the site untouched with the contamination still present.
The scrap yard site also presents environmental challenges which will require careful treatment.
All of the current buildings on the site (with the exception of the offices in the South East corner of the site) were designed for industrial processes. It is not, therefore, straightforward to convert them to uses which involve occupation by people. Some have few windows or other external openings, some are very narrow in plan and some very deep. Their condition is also very variable - some remaining sound, others in perilous condition.
The site presents a number of challenges which make it far less straightforward to develop than the large newbuild developments taking place elsewhere in Leith. We believe that the only way to meet these challenges is to understand the history of the site, to identify its key characteristics, and create a bespoke development which preserves the best of these characteristics.
Answering the Challenges
Clearly it is only possible to develop the site, and produce the new accommodation and jobs it would provide, if an approved scheme is financially viable. Within the challenging constraints of the site our strategy is as follows:
Reduce existing environmental problems (noise, dust, vibration) by including the current scrap yard in the develoment
Where possible avoid site disturbance to minimise the need to remove contaminated material from site (relying instead upon encapsulation or on-site treatment).
Concentrate on the preservation and reuse of the most important and characteristic buildings.
The western gasholder is so altered that it bears little relationship to its historic origins. In its current form it could not be converted economically because of the almost complete absence of windows. We therefore propose its removal
New buildings should be of high quality and bespoke form to respect the industrial heritage of the site
Such a strategy would allow the preservation and reuse of the most important buildings on the site, and create a development which strongly reflected the historic nature of the site.