When the HBV fails, it can cause fracture of the plastic body which then leaks water, or it may be simply split/cracked hoses. This water tends to drip off the back of the sump under the car.
If you have water actually dripping from the auxiliary belt area, ie. down the front of engine, then it could be that the seal between your water pump and the engine block has failed, (the pump is bolted onto the block and a rubber ring seals the joint between the pump and the hole in the block when bolted up), or more likely, the gland seal on the pump itself has packed up, letting water leak out round the pump shaft. The water pump on the V6 is driven by the aux. belt which makes it a relatively simple job to replace, and you could follow the maintenance guides on here to do it yourself.
You should first check closely that the problem isn't as simple as a split hose on the radiator or on the throttle body, or even the pipes from the expansion tank. Have a look with the engine running but keep fingers, hair, scarves etc. well clear.
I know the Haynes manual has caused you uncertainty in the past, but do see if it helps in this instance to identify pipes etc.
Good luck.
Bill.