Is there a better way to access this pressure tank?

[C & E]

My pressure tank resides in a 4' diameter corrugated section of pipe and about 4' below ground level. The pipe extends above ground about 12" on the uphill side and 16" on the downhill side. When I bought the property there was a piece of plywood over the pipe and a tarp over that. The previous owner said that he hadn't had any problem with freezing in the 6 years it was there. OTOH, we haven't had a bad winter in those years either. Being suspicious I decide to put in place a 4" thick x 4' dia beadboard disc for insulation. OK, that's the backround (sheesh!) I need to install a water filtration system in that hole but can't imagine having to go through all that material every time I need to change a filter. The house is a new double wide that we use for a cabin and the underside is well sealed and the main entry point isn't very evident inside the house. Not too sure how to locate that. What do you think is the best option? Please don't suggest calling the people I bought the house from. They installed it backwards (facing the wrong way) and it got ugly before I got my way. They don't want anything to do with me (imagine!). Apologies in advance for the long story.

[Edwin Pawlowski]

I'd put the filter inside at the point of entry.

[fisherman206]

Your first job is to locate the place the pipe enters the house. You should know where it is anyhow. If a pipe breaks and you start flooding, you dont want to hunt down the then. You want to find it NOW. Find it, then put the filter there.

Look near the water heater for starters. Sometimes there is a label on the outside of the building. Look for an indent in the lawn where the trench was run. It cant be that hard to find, just trace the pipes. There is likely a closet and often behind a bathroom. Once again, look for the water heater.

The first thing all homeowners and renters should know is where to shut off the main water valve, the main gas valve, and the main breaker. It's time you find them. Shut off your computer NOW, and go look....

[C & E]

Thanks. You and Ed are right about knowing where the water comes into the cabin. I didn't see it when I had the panels down to get to the water heater but then again, I wasn't looking for it. These places are built as 'economically' as possible - in terms of money and space. Whereever it is I'm betting that there is very limited space to install but I haven't given up on the idea. It is the better place and would save having to build an enclosure over the tank and insulate it. I'll be there for the Memorial Day holiday and give it a going over. Sorry it was stupid question - I had a brain fixation on that dang pipe in the ground.