The Davidson Paper Mill (also known as Muggiemoss Mill) was a major employer in Aberdeen for over 200 years. First established in 1796, the mill finally closed in June 2005.

Client Barratt Homes
Project Preparation of a contaminated industrial site prior to redevelopment for housing.
Outline scope of works Diversion of a 900mm concrete combined sewer. Ground works in an area with heavy industrial contamination. Construction of a storm cell water storage tank.
Dates March 2014 to July 2015
Headlines

Diversion of 900mm concrete sewer in difficult ground conditions which didn’t allow for shoring.

Close co-operation with local residents and Aberdeen City Council to minimise disruption

Use of suction excavation to avoid damaging existing services

The scale of the manufacturing activity on the site can be seen from the aerial photograph taken in 1998. After the mill’s demise Muggiemoss Road became a popular route for commuters trying to avoid congestion on Aberdeen’s main arterial routes.

The works required the closure of Muggiemoss Road for 13 weeks. Close liaison with Aberdeen City Council ensured traffic disruption for commuters and, in particular, local residents was minimised. A key time parameter was that the road had to be reopened in time for the Scottish Golf Open.

W M Donald’s task, in outline, was to undertake key preparatory works such that the site could be developed for housing. The manufacturing plant and buildings had already been demolished, however the site was contaminated with asbestos, heavy metals and ash: part of the site was referred to as ‘Cinders Hill’!  Consequently all excavated materials had to be validated and assessed by an environmental engineer.

Key to the redevelopment of the site was the diversion of a 900mm concrete combined sewer and the construction of a large Stormcell© stormwater storage tank, an engineered SUDS (Sustainable Urban Drainage System) solution. These works were critical as the flow in the sewer increased from 40l/sec in dry conditions to over 240l/sec during heavy rainfall!

Work on the industrial site was complicated by the discovery of multiple uncharted services including many ancient brick culverts. This situation was replicated by the complex network of services under the road – the location for the redirected sewer – which meant the use of shoring was limited. Extensive use of suction excavation techniques ensured there was minimal damage to services (see engineering commentary below).

W M Donald also provided the tracking in which the utility contractor could install new services as housebuilding progressed.

Scope of Works

  • Inspection, testing and validation of bulk earthwork materials
  • Diversion of existing ‘live’ combined sewers
  • Complex tie-in to existing live sewers including overpumping of existing flows
  • Services diversions
  • Reconstruction of existing carriageways

Engineering Commentary

This project proved the worth of suction excavation techniques in safely locating and sensitively excavating materials around a complex labyrinth of gas, water, and electricity services.

Learning Points

"Civil engineering is rarely, if ever, an exact science. Success on this project was achieved by responding quickly and flexibly to a series of unforeseen challenges. In particular, to the presence of uncharted services and ancient brick culverts. We countered this by having an engineer permanently on site responsible for setting out and monitoring line and level of ongoing works.

From a planning perspective, in retrospect it would have been preferable for services to have been diverted before we started on site.
"

Ewan Riddoch – Technical Director

Download this case
study as a PDF