We had a customer who had a 100 year old + inspection chamber where the channels were made from concrete. Over time the channels were no longer functional due to having large holes in them which were causing the customer to have continuous blocks in the chamber and having to regularly clear them out. Also the raw sewage was seeping into the earth beneath the channels now they had worn away so badly.
In the photograph you can see the improvement we made to the inspection chamber, we knocked out all of the old concrete and replaced it with the plastic pipes, this will last the customer another 100 years at least!