Context

The effectiveness of Siltbuster as a critical supplier and natural partner to a valued client and the customer benefits of its close relationship with Selwood, were highlighted when an issue threatened to put a sewage treatment works in the North West of England out of compliance.

The facility is a vital asset for the client, treating wastewater to protect water quality in the River Alt and surrounding areas, including bathing waters.

Water treatment specialists from Siltbuster, working closely with pump rental specialists from Selwood, a sister company in the Workdry International Group, stepped in quickly to put in place a sidestream solution as an emergency response.

The project was implemented with just 2 weeks’ duration from conception to completion.

Challenge

The client reported to Siltbuster that a hydraulic restriction was causing existing systems at the site to become overwhelmed. The issue put the site at risk of non-compliance for Flow to Full Treatment (FFT) and levels of ammonia which would be harmful to the environment.

Initially, Siltbuster was asked to scope a solution as planned works, but this quickly developed into an emergency response, requiring multiple partners to deliver at pace.

The client required a modular sidestream installation capable of handling peak flows of 65 litres per second, treating contaminants to produce a discharge quality of 30mg/l Biological Oxygen Demand (BOD), 45mg/l suspended solids and 5mg/l of ammonia.

The urgency of the solution meant that a rental solution had to be quickly installed, but the longer-term aim was to create a permanent sidestream solution.

Alongside the time-critical nature of the delivery, on-site space constraints which limited the area for equipment and construction of the solution also had to be considered.

Solution

Siltbuster’s engineers devised a bespoke, modular solution comprising three Moving Bed Biofilm Reactors (MBBRs), and three Dissolved Air Flotation (DAF) units with integral whitewater and desludge pumps.

As with all Siltbuster equipment, the plant was pre-assembled and factory-tested at its HQ before being delivered to site – reducing the time and disruption associated with installation on site.

The MBBRs provide packaged plug-and-play aerobic biological treatment, using media with a large specific surface area to capture contaminants, while blowers deliver an even air distribution to maximise oxygen transfer efficiency. MBBRs are especially efficient in areas where space is limited, providing up to twice the capacity in the same footprint when compared to alternatives such as submerged aerated filters.

Treated water was moved from the MBBRs into the DAF tanks for a second stage of treatment. These units are designed to separate suspended solids, including organic matter, using air bubbles to encourage the contaminants to float. The use of whitewater instead of compressed air increases the efficiency of the units and also reduces noise levels.

Selwood assisted the project with quickly-deployed pumping support, providing equipment to feed the Siltbuster units and to take the treated effluent back to the discharge well. Selwood also worked closely with the UU team to find spare power on site, removing the need for generators – which helped reduce hire costs and minimise the environmental impact of the installation.

Result

The project took just 2 weeks from conception to completion – one week for commissioning, and another for installation – highlighting Siltbuster’s ability to deliver effective solutions in short timescales.

Siltbuster’s close relationship with the Selwood team was a crucial factor in being able to deploy so quickly, as was the collaborative approach taken by the entire team – for example, joining three progress calls a week between Siltbuster, the client and Selwood project teams to ensure the programme was maintained.

Project teams worked through weekends to ensure the system was operational by the deadline and the treatment system remains in place, ensuring site compliance is maintained, with ammonia levels from the sidestream remaining lower than 0.5mg/l, and no reported breakdowns or flow interruptions.

Siltbuster will now work with the client to consider the development of a more permanent sidestream solution at the site.