does anyone know of an approved method of plugging the end of a pipe in a cabinet.

I have 3 pvc 4" pipes coming into a main service disconnect feeding a building. One of the pipes has a very small leak but over the last 10 years has caused corrosion on the breaker and buss bars and the unit has to be replaced. We are trying to avoid ripping up 120' of parking lot to replace one of the pipes and the additional down time to the building. I know I cant just stuff hydro lock concrete into the end but I was wondering if there is a UL listed and approved product or if we have no choice but to rip it up.

I am not on the hook for the original job in any way and I could use the extra work but the decision is up to an association of doctors and you know how they can be.

I would like to present 2 options instead of loosing the job altogether.