I bought a whole house water filter to hook up to the main water line. The plumber who came in said that he won't be able to install it because the pipe that comes from the ground hooked up to the copper pipe is plastic.
He says that this plastic is usually not used for that kind of water pressure for the main line and can burst at any time. If he starts cutting the pipe above it to hook up the water filter, there is a potential that the plastic could break/leak due to all the shaking etc. He has asked me to contact the builder/home inspector (as it shouldn't have passed the home inspection like that? ) and take care of this first.
Picture is below. The black color pipe is the one in question. Has anyone seen plastic pipes come up from the ground like that to the main line? Will it burst?
Update – new pics and details
Close up pictures on request. I looked the pipe closely. It is written 1 1/2" 0.1 / Plastic. (above the first ring at the bottom, you can see it in the second pic).
House is built in 1993.
Best Answer
Though it may seem odd, it is possible the plumber knows what he's talking about. If this is a Polybutylene pipe, it could indeed be brittle and fail if it's jostled during the installation of the filter.
It's impossible to tell from the picture what type of pipe that is, but based on the plumbers concern I'd guess it is Polybutylene.
Polybutylene
Polybutylene was used in pipes between about 1980-1994/5, and was commonly used as supply line in the 80's. It was found (in some cases) to react with oxidants in the water supply, which caused the pipe to become brittle and fail. To my knowledge, this type of piping is no longer used. Though if the house was built; or there was supply line work done, during the 80's, it's likely this is Polybutylene pipe.
High Density Polyethylene
Don't confuse Polybutylene pipe with Polyethylene pipe. High-density polyethylene is commonly used as water supply line today, and is stable and safe to use.
Cross-linked polyethylene
Cross-linked polyethylene (PEX) is not typically used as an underground supply line, as it can sometimes react with minerals in the soil. Where PEX is used underground, it's typically encased in sand (or other non-reactive materials) to prevent negative reactions. Because of this it's often more expensive to bury PEX, so other materials are used instead.
How can I tell what it is?
The only way to be sure what type of pipe this is, is to look for markings on the pipe itself. Polybutylene will be marked
PB####, Polyethylene will be markedPE####, Cross-linked polyethylene will be markedPEX-x(where x = A, B, or C).