Equipotential bonding - advice for plastic/copper

[ozymandias]

Hi all.
My situation is this:
I have a 25mm MDPE rising water main in the cellar. This has been cut to include a 1m copper section which used to have a water softener attached (no longer!). The copper then returns to MDPE and dives underground rising again in the garden, changing back to copper and entering the building.

Currently the only earth bonding is in the bathroom where a shower pump is situated. I am updating this.

We are undertaking a cellar conversion, and will need a wash basin and wc in the cellar (saniflow type). The mains cold for this could come from elsewhere in the house (long run) or just from across the cellar... but if I do the run across the cellar in plastic, presumaby there's no point in earth bonding 1m of copper??

Alternately I could change the short copper run back to MDPE and properly bond the copper where it enters the building. If I then decided to take a tee across the cellar (in plastic from MDPE) would I be right in thinking that this is OK as long as the main IS earth bonded when it changes to copper?

To summarise, can I take a tee in plastic well before the point where the MDPE pipe changes to copper and then earth bond within 600mm of it becoming copper??

Suggestions welcomed!

 

[equitum]

You do not need any bonding in the cellar conversion as it is not a special loacation, i.e. a room containing a bath or shower.
You should main bond the cold water supply where it enters the cellar on the copper with 10mm back to the MET, or alternatively replace the copper section with plastic (I assume thats MDPE) and then no bonding required here.

Where the water service re-enters the house you should main bond this also back to the MET in 10mm.