Our latest foray into Wiltshire Federation's events wasn't the bog standard offering! Six Pewsham Belles proved they look stylish wherever they go, even when it involves hivis and Trowbridge sewage treatment works. It proved an mind boggling and fascinating visit. We may simply flush our waste away, but the ensuing process of dealing with it is quite complex. The waste is screened (twice), settled in tanks, then digested by beneficial organisms (in two different ways), before the much cleaner waste water is discharged into the local river. This discharge occurs no matter how low the flow in the river may be and adheres to strict standards which are monitored by the Environment Agency. We also learned the works takes waste from 60,000 homes and can generate enough biogas to fuel 2,500 of them. Any left over waste solids are sold to farmers as a soil improver and the screenings are composted. Wessex Water is also involved in research projects looking at the 'plastic soup' problem, but it soon became clear a solution at the treatment works level may help, but it won't solve the problem entirely. Imagine the small diameter screens needed to filter out microplastics... it would slow down the process considerably and require much larger tanks to store the waste in the interim. A similar process could be done at the home level, but would rely on everyone cleaning their filters so they don't become blocked. Would we do that?
And then... not all waste water undergoes sewage treatment. A huge amount of it is discharged directly into the nearest water course via, for example, road runoff and drains, which contains materials from tyre wear, diesel spillage and anything else people choose to put down the drains. It's also another potential source of plastic from the careless dumping of rubbish.
There is a Yellow Fish scheme designed to raise awareness of this problem, and Wiltshire Wildlife Trust is a key champion for our county. The campaign first started in Canada, spread to the USA, and is now over here. The link takes you to a blog post showing how Wiltshire Wildlife Trust is implementing the scheme.
Whilst we learned a lot, it wasn't all serious on the day. We all giggled when we saw the sign in the photo, bearing in mind where we were. Lunch afterwards at the Milk Churn also gave us time for a good catch up with each other and time to reflect on our visit.