Good morning all

We carry out water jetting for cleaning drains (sewer cleaning) and use harben pumps with a pulse jet (jump jet) facility, this basically pulses the water causing the jetting hose to be able to reach further distances up a pipe. With this facility there is HAV issues, I have had a HAV consultant at our depot (yesterday) to measure the M/S2 and the readings were interesting to say the least and are considerable over the EAV & ELV. Obviously we are looking at new ways to carry out the works, health surveillance by an occupational health expert etc.

Is there anyone else out there that uses water jetting and also the jump jet and has used adequate control measure to reduce hand contact time, I would be interesting in bench marking with you please. Thanks Shaun.

Shaun, I haven’t any experience of water jetting however, the measurement of vibration levels is ‘notoriously’ difficult with often significant variation between subsequent readings on the same kit using the same kit. Has your consultant also provided you with the ‘uncertainty’ or ‘K’ value? It is important that you try to get accurate figures for the vibration level as this can (obviously) have a significant effect on the overall exposure and any subsequent mitigation. You might therefore also want to try and source some ‘operational’ vibration values from a commercial database to try and get a comparison with your current measured values. It is rather fraught with difficulty and I think that the HSE recognise this.

The measurements that your consultant has taken cannot in themselves be “ over the EAV & ELV.”, although they will determine ‘when the EAV & ELV will be reached.

I am not sure of the benefit of ‘benchmarking’ with others would be; I’m not sure if compliance with the requirements of the regs is a benchmarking exercise.

As I have said, I don’t have any real experience of water jetting but realistically you need to reduce the exposure time and on the face of it, it appears that you need to devise some method of going ‘hands off’ with the kit. Not sure how practical that is though.