PROJECTS
Project: Medical waste processing plant
Location: Stafford Park, Telford, Shropshire
Client: Stericycle waste management
Services: Flood risk, drainage design and hydrology
Our flood planning and drainage expertise was instrumental in turning existing industrial premises into a plant for the treatment and processing of hazardous medical waste generated from hospitals, dental surgeries, GP surgeries and other health environments.
The outgoing tenant of this 3-acre industrial site made aluminium window frames. The incoming tenant – our client Stericycle – is a leading medical waste processing and disposal company. Our input was needed in planning a compliant drainage system capable of safely discharging potentially contaminated surface water into the foul sewer, in accordance with Environment Agency protocols.
We also had to ensure that any surface water not at risk of contamination is discharged into a storm sewer. In addition, we were asked for a strategy to contain the high volumes of water that might be expected in the event of tackling a fire at the plant, within the site extents, to avoid a potential pollution incident.
It took just six months from us being called in by Stericycle, for the plant to become fully operational and signed off by the local authority, Severn Trent and the Environment Agency. Through engagement, negotiation and building trust with the water authority, we could clarify the details of the drainage system.
We produced layout plans, construction details and model pipe networks; plus delivered drainage calculations and supplied flood risk assessments to meet stringent conditions set by the local planning authority, the water authority (Severn Trent) and the Environment Agency.
Although medical waste arrives at the site bagged and sealed, it’s crucial that, in the unlikely event of a leak, the storm drain isn’t contaminated by rainfall runoff from the processing plant’s service yards. We had to design a failsafe system which would keep clean surface water segregated from potentially polluted water.
In this way, we created a split system where rainwater falling on areas like the roof, where there was at no risk of contamination, could be discharged safely through the storm drains. But rainwater collecting in the service yard had was directed to the foul sewer due to the risk of contamination.
The second part of our brief was to devise a strategy in the event of a fire at the plant: how to retain and discharge the high volume of water that might typically accumulate after a two-hour firefight. The Environment Agency requires that no water from premises handling hazardous waste should leave the site or permeate the ground.
We therefore designed a system that effectively sealed off the site with six penstocks (sluice gates), ensuring that any contaminated water remains on site after a fire; allowing specialist tankers to take away the polluted water after the event.
The third task was to produce drawings to support Stericycle’s application to Severn Trent for a trade effluent consent, allowing for industry generated foul sewage. Our drainage network modelling addressed an existing concern from the local authority, that surface water ponding in a 1-in-100-years rainfall event might result in pooling of contaminated water in the service yards. The solution here was an attenuation system (underground stormwater storage tanks).
Calibro were fantastic to collaborate with during the application process. They worked tirelessly and in a friendly manner to help us overcome obstacles and produce an efficient scheme and strategy. Calibro took a pragmatic approach to solving the site’s complications, and were responsive to our requirements and needs.
