The Aero-Fac® Sludge Digestion System (SDS) at Sandringham solves the issues of sludge handling and disposal, as well as peak flow and load issues.
The Royal Estate at Sandringham presented a challenge for wastewater treatment. While the Estate and the adjacent village of West Newton could have a normal population equivalent of 650 residents contributing to the treatment plant, it was the large influx of visitors to the area in the summer months that presented the main concern.
Sandringham Reception Centre
Sandringham is, of course, a very popular spot for tourists. The visitors centre can see a throughput of on average 2,000 people per day during the summer months. With summer events such as the flower show, where attendance could be as much as 25,000 over two days, plus weather and other factors playing a role, no one could accurately predict when the influx would suddenly appear. These very popular events were not something the existing plant type could easily be designed to accommodate.
Gurney Environmental engineers worked with the Estate for over a year on a solution to their needs for wastewater treatment and sludge handling — a solution that would meet modern effluent standards, but could react to sudden peak flows and loads without the need for an operator on hand.
Furthermore, the plant must be odour free, produce no sludge of its own for routine handling and disposal, AND digest all sludge from the existing mechanical plant. Eliminating sludge lorry movements in and out of the plant would save time, noise, traffic on small local roads, money and cut carbon emissions — all in all, a very green approach to total on-site sewage treatment.
A No-Sludge System
The Aero-Fac® SDS system was selected for the Sandringham plant. The existing oxidation ditch was refurbished at the time and integrated into the new scheme. Flows are split between the Aero-Fac® and the ditch with surges in loading being diverted to the Aero-Fac®, thus allowing a nice, uniform flow to go to the less-flexible ditch. All sludge produced by the ditch is sent to the Aero-Fac® cell for total digestion, which eliminates sludge storage, handling and disposal.
The existing oxidation ditch required routine sludge removal and disposal. The ditch was refurbished as part of the Aero-Fac® SDS upgrade project.
Designing Wastewater Treatment Plants for Real-World Conditions
The Sandringham installation exemplifies one of the major benefits of the Aero-Fac® systems. Whether from storm flows, tourists or industry, many plants can experience massive shock or peak flows and loads. Aero-Fac® has the unique ability to accept these flows with no warning and no operator intervention needed. The SDS version of Aero-Fac® also eliminates sludge processing, handling and disposal issues and costs.
Top: Construction of the Aero-Fac® SDS cell included a liner. Simple cell construction is quick allowing fast-tracking of projects. Bottom Left: Final treatment cell utilising a single wind/electric powered aerator and a low pressure fan blower. Bottom Right: Final effluent from the cell is highly stabilised and well suited for irrigation.
And Aero-Fac® can do so without the common odours associated with sewage treatment. Eliminating sludge removal, conditioning handling and disposal saves up to 50% of the operating costs of a typical plant, while also eliminating the onerous regulations regarding sludge that are tightening throughout the world.
Low Ops/Maintenance Requirements
Unlike the old oxidation ditch, the new Aero-Fac® SDS cell requires almost no operator attention or significant maintenance. Occasional inspection and replenishment of the lubrication unit on the windpowered aerator and an annual shot of grease for the diffused air low pressure centrifugal fan blower motor are about it. The blower itself has almost no wear factor since it is low pressure and not a typical positive displacement blower.
Lower Cost Option Solves Problem Better!
When it came to the selection of a new wastewater treatment plant for Sandringham, while cost was one of the concerns, it was the overall extremely low total lifetime cost afforded by the Aero-Fac® system, coupled with its unique ability to handle massive peak loads and flows, and do so without odour, without a visual eyesore and without sludge handling that made the decision obvious for the Estate.