Sewer lives - 2,000 years?!
Interesting report from Salmon and Trout Conservation and the Angling Trust. Prepared to put pressure on regulator Ofwat for the next Price Review in 2024 (Preparations start early, even for five yearly reviews). As they say: 'the case for increased investment in water and 'shadow' strategic priorities for Ofwat'. For as they rightly say 'Without a step change in investment, which can only occur with the support of OFWAT, the situation will
only worsen with dire economic and environmental consequences.' This having found that 'England has seen the proportion of water bodies achieving Good Ecological
Status fall from a modest 22% in 2009 to a dreadful 14% in 2019.'
“During wet weather, storm overflows act to prevent sewers becoming overloaded with a combination of sewage and rain and release diluted wastewater into rivers. However, their use has increased in recent years as climate change has led to greater rainfall and water infrastructure has not kept pace with population growth”.
What also caught my attention was their calculation of sewer replacement rates - that is the life of our sewers. When I last tried to calculate it from Ofwat figures the answer was about 300 years.
This report finds that "an examination of the data on water company pipe replacement rates reveals just how long the regulator is expecting us to keep using our existing sewers and associated assets. Unbelievably the typical replacement/renewal rate is around 0.05% of the network per annum – which implies we are expecting sewers to last for 2,000 years!"
"By comparison, European averages show most countries have a replacement rate of around 0.5% each year, an expected life of 200 years."
And "For context, we know that modern PVC pipes can last between 50-100 years depending on various environmental factors such as ground conditions."